Explore the contradiction between computing power and algorithm
Publish: 2021-05-02 09:27:10
1. First of all, understand and firmly grasp the basic knowledge. That is, the basic knowledge related to computing power, mainly refers to mathematical concepts, operation laws, operation properties, operation rules and calculation formulas. It is difficult for students to understand some calculation rules. In teaching, teachers should not be in a hurry for success, but should help students to master basic knowledge as a breakthrough, disperse and break through difficulties. For example, when teaching the addition and subtraction method of different denominator fractions, first of all, let students understand that the denominator is different, that is, the units of fractions are different. If the units of fractions are different, they can't add and subtract directly. When they understand this truth, they can guide students to use the knowledge of general score to change the different denominator fractions into the same denominator fractions, so the problem turns into the addition and subtraction of the same denominator fractions that they have learned
Second, strengthen the practice and basic skills training. In the calculation practice, strengthening the basic skills training is an important step to improve the calculation ability. In addition, in the calculation practice, we should help students summarize some regular things, so that they can skillfully use the basic knowledge to calculate, and constantly improve their calculation ability. In addition, the forms of calculation exercises should be diversified, and the forms should serve the content. However, we should pay attention to the quantity of exercises. We can't do the opposite as long as we don't pay attention to the quantity and quality. Some students lack the spirit of diligent learning, and the calculation itself is boring and lack of plot. When students encounter a large number of questions, they are easy to resist and unwilling to calculate, which can seriously affect students' interest in learning mathematics. In teaching, as teachers, we should simplify the topic selection, Try to find some simple calculation problems to guide students to do abstruse calculation problems
thirdly, cultivate students' good study habits. Good learning habits are the guarantee to improve the accuracy of calculation. First of all, students are required to carefully review the calculation, and do not blindly simplify the calculation without reviewing the operation order, such as 15 + 5 × 5), the students mistakenly calculated it as 20 × Secondly, the calculation process should be strictly standardized. When solving problems, students are required to have standard calculation format, neat writing, clean homework and paper surface. Even the draft should be written neatly and clearly. When students make mistakes in calculation, students should not only check the calculation process, but also find out whether there are errors in the draft. For example; The alignment of digits, whether the carry is added or not. Let the students form the habit of self checking in calculation< Fourth, strengthen the cultivation of the ability of oral calculation.
calculation is the basis of estimation and written calculation. Any four item mixed calculation problem is synthesized by the oral calculation problem of the main road. The correctness and rapidity of oral calculation directly affect the improvement of the calculation ability. When designing oral calculation exercises, we should be targeted, from easy to difficult, and graally improve them, including some simple calculation problems, It is helpful to train students' thinking flexibility to do oral arithmetic exercises frequently.
Second, strengthen the practice and basic skills training. In the calculation practice, strengthening the basic skills training is an important step to improve the calculation ability. In addition, in the calculation practice, we should help students summarize some regular things, so that they can skillfully use the basic knowledge to calculate, and constantly improve their calculation ability. In addition, the forms of calculation exercises should be diversified, and the forms should serve the content. However, we should pay attention to the quantity of exercises. We can't do the opposite as long as we don't pay attention to the quantity and quality. Some students lack the spirit of diligent learning, and the calculation itself is boring and lack of plot. When students encounter a large number of questions, they are easy to resist and unwilling to calculate, which can seriously affect students' interest in learning mathematics. In teaching, as teachers, we should simplify the topic selection, Try to find some simple calculation problems to guide students to do abstruse calculation problems
thirdly, cultivate students' good study habits. Good learning habits are the guarantee to improve the accuracy of calculation. First of all, students are required to carefully review the calculation, and do not blindly simplify the calculation without reviewing the operation order, such as 15 + 5 × 5), the students mistakenly calculated it as 20 × Secondly, the calculation process should be strictly standardized. When solving problems, students are required to have standard calculation format, neat writing, clean homework and paper surface. Even the draft should be written neatly and clearly. When students make mistakes in calculation, students should not only check the calculation process, but also find out whether there are errors in the draft. For example; The alignment of digits, whether the carry is added or not. Let the students form the habit of self checking in calculation< Fourth, strengthen the cultivation of the ability of oral calculation.
calculation is the basis of estimation and written calculation. Any four item mixed calculation problem is synthesized by the oral calculation problem of the main road. The correctness and rapidity of oral calculation directly affect the improvement of the calculation ability. When designing oral calculation exercises, we should be targeted, from easy to difficult, and graally improve them, including some simple calculation problems, It is helpful to train students' thinking flexibility to do oral arithmetic exercises frequently.
2. Hello, there is no bitcoin futures on domestic regular futures platform, so investment should be cautious.
3. In chain answer:
ICO is a way to invest in early-stage projects with cryptocurrency. Corresponding to IPO, ICO is also a kind of "public offering" in essence. It only changes the subject matter of IPO from securities to digital cryptocurrency
with the increasing popularity of blockchain, there are more and more ICO projects, but most of the ICO projects are not applied, or even have no application direction, just a simple white paper. Such ICO projects are almost unreliable
in many domestic ICO projects, there are many reliable ones that have been completed and have not yet started. The price of its token varies from high to low, including printing chain, etc. with anti-counterfeiting traceability as the starting point, it will build a general public chain for commercial applications
however, with the increase of ICO projects, the inevitability of being regulated also highlights. Only the real landing application can carry out ICO in the future and survive for a long time.
ICO is a way to invest in early-stage projects with cryptocurrency. Corresponding to IPO, ICO is also a kind of "public offering" in essence. It only changes the subject matter of IPO from securities to digital cryptocurrency
with the increasing popularity of blockchain, there are more and more ICO projects, but most of the ICO projects are not applied, or even have no application direction, just a simple white paper. Such ICO projects are almost unreliable
in many domestic ICO projects, there are many reliable ones that have been completed and have not yet started. The price of its token varies from high to low, including printing chain, etc. with anti-counterfeiting traceability as the starting point, it will build a general public chain for commercial applications
however, with the increase of ICO projects, the inevitability of being regulated also highlights. Only the real landing application can carry out ICO in the future and survive for a long time.
4. In my opinion, the resistance to accelerating air is a variable force, which is why we consider it from the angle of energy rather than from the angle of resistance integral. According to your method, we know that P = FV is actually the instantaneous power when the force pulls a certain mass of object, but we should know that in different times, with the acceleration of speed, more air is compressed to do work per unit time, so this formula is not applicable. From the problem solution, in DT time, through the consideration of energy conversion, it is really accurate, which is the real embodiment of instantaneous power
I am about to graate from University, so I use differential to understand the infinitesimal method
I am about to graate from University, so I use differential to understand the infinitesimal method
5. In the list of autonomous driving technology companies released by Navigant research in 2019, amberful ranked fourth, closely behind the platitudes of Google waymo, GM cruise and Ford
strictly speaking, this company has just turned 2 years old
on December 5, 2017, after Delphi split its powertrain business, Delphi officially unveiled its new company name, APTIV PLC, and announced that it focused on accelerating the commercialization process in the fields of active safety, automatic driving, improving driving experience and Internet services
in other words, Delphi, a traditional auto parts manufacturer, intends to devote a considerable part of its energy to the "brain" and "nervous system" of cars, such as the software, algorithms, and car architecture needed for automatic driving
according to the official statement, in the four or five years since the company first entered the field of automatic driving, everything has gone smoothly:
in 2015, amber Ford completed the automatic driving test across the mainland of the United States, becoming the first company in the world to launch the commercial project of automatic driving
in May 2018, amber and LYFT cooperated to launch the commercial operation project of automatic driving, and launched the public oriented automatic driving network car Hailing service in Las Vegas
as of September 2019, the company has provided more than 70000 person times of automatic driving network car Hailing service and obtained a passenger satisfaction score of 4.95 (full score of 5). At present, commercial development projects of automatic driving have been carried out in Las Vegas, Boston and Singapore
naturally, amber has graally extended its tentacles to the research and development of L4 automatic driving. At this time, the team found that in order to achieve high-level automatic driving and mass proction, the current automotive infrastructure is far from meeting the demand
so Yang Xiaoming, President of Asia Pacific region, shared his own design concept. At the same time, he also discussed with Che Yunjun the feasible business model in the future and the prospect of the automatic driving instry -
the birth of a new supply relationship
Q: please give us a brief introction of the new generation infrastructure of amber, and what stage has the cooperation reached at present
Yang Xiaoming: at present, the traditional way of automobile architecture design is nearly saturated, and the architecture design must go to the next generation, innovation and reform
the direction of electric vehicles has been proved, especially in the Chinese market. Tesla's success has proved that pure electric vehicles are the development direction. The application speed of the new architecture on electric vehicles may be faster, because it is relatively simple, and there is no complex powertrain mole such as traditional fuel vehicle powertrain
at present, our procts have appeared in CES 2020, and are no longer in the stage of concept. At the same time, such innovative and revolutionary ideas and procts can not be put in place in one step. Now many ideas have begun to be promoted in the current new projects and applied locally, including the graal rection of moles in some customer models and the graal change to the direction of domain control
Q: as far as I know, many manufacturers are studying the domain controller. When will the procts of anbofu be launched
Yang Xiaoming: in this year's CES, we have exhibited a comprehensive range of procts, including domain controllers, computing control centers, etc. We are discussing with some customers, including traditional vehicle manufacturers and new force car manufacturers. There will be some conflicts between new technology and previous procts at the design level. The new technology has a characteristic that its cycle is much faster than the traditional car development in previous years, so the time is very short. And the Chinese market also has a characteristic, local enterprises to accept new technologies, new concepts quickly, once it will move quickly
Q: when this architecture is implemented in mass proction, what requirements will it put forward for chip and computing power modification
Yang Xiaoming: higher requirements are required for chips, but the cost of chips is not a problem at present, because the technology is developing very fast, and the most important problem is the system. The control system of anbofo is based on an open architecture, which avoids the difficulties caused by the lack of unified standards in the future. So the chip is definitely upgrading. The function of the chip is much faster and bigger than that of the previous ECU chip, but the most important thing is an open operation system, OS system
as far as the auto driving scheme is concerned, there are two major directions for discussion. One is to put all the computing power on the sensors and cameras. At present, many vehicle applications do this. But it will face a very big problem. In case of equipment failure, the maintenance cost will be very high. Take the sensor as an example, now every sensor has a chip, and the cost of maintenance is very high
the other direction is the route of sensor fusion, which sends the processing and information to the central area block and the computing center for processing. At present, this may be a feasible direction, but it still needs an evolutionary process
Q: what are the differences between domestic and foreign electronic and electrical architecture systems? Are there any differences? Does China's architecture also need to adapt to localization standards<
Yang Xiaoming: there is no regional difference in the electronic and electrical architecture, but China certainly has its particularity. From the perspective of architecture, we don't think there are big differences in architecture. There may be slight differences in the requirements of laws and regulations in different countries
reporter: the logic of the evolution of electronic and electrical architecture of many auto companies is to transform to the software level. How to balance the contradiction between suppliers and OEMs
Yang Xiaoming: This is not a contradiction, but a new model and the instrial chain reform it brings. In the process of building a new instrial chain, we must quickly define which end of the instrial chain we are at, which is very critical. For example, we are a system supplier. Many of our advantages lie in the calculation of hardware and software. We also do many ECU programs, and we are also doing software
in the end, the purpose of OEM software will be different from ours, because we are controlling cars, and their software will focus more on the needs of end customers: what kind of applications do car owners need? They want to make the end customer experience and customer demand software very well, and the profits brought by software are unimaginable
the future business model of autonomous driving
Yang Xiaoming: we have 75 vehicles in operation in Las Vegas, which are completely running every day. Passengers can call the self driving taxi of anbofu through the taxi software. So it's completely commercial operation, not a demonstration. We've passed this stage
recently, the scope of operation has been extended to the airport, which is of great significance to the operation of self driving shared car, because in the past, the airport was not unable to do it, but the security inspection had a lot of worries about self driving, and the whole approval process was relatively long. By the end of last year, there had been 70000 times of driving, and the growth rate was very fast. The performance of automatic driving was also very smooth and safe. Nine out of 10 passengers said that they would choose our automatic driving taxi again
in recent years, the instry has been discussing how to expand the business model of automatic driving. Nowadays, the same situation is also faced in China. You can't rely on the government forever. It can't achieve sustainable development. So we chose to work with LYFT to explore a sustainable business model. There are many applicable scenarios in China, which are easier than those in foreign countries
now practitioners are flocking to research algorithms and AI. I think the more important thing is how to find a successful business model, what role the host plant should play, what role the system supplier should play, and what role the software supplier should play
secondly, we have been calling for the government's laws and regulations to be kept up with, and the laws and regulations should be focused on. I feel that the domestic government is often in a passive mode of response and is often forced to come up with a special way to grant a piece of land and open up an area. Las Vegas, for example, has a certain legal support. The legal advisers of the state government meet with enterprises regularly. In particular, autonomous driving companies like us have a meeting to discuss what problems will arise in the future, what problems are unclear at the present legal level, and how to match laws and regulations. This is worth learning in China. Otherwise, only a few dozen or a few hundred of them will be able to work out the commercial environment of automatic driving
Q: in the cooperation with LYFT and Hyundai Auto, what is the business model that amberful explored
Yang Xiaoming: These are two different kinds of cooperation. They are the cooperation with LYFT for the commercial landing of automatic driving, and they launch automatic driving on the shared travel platform. Shared travel will occupy a large proportion in the future mobile travel business. At the same time, how to use the idle period of vehicles is in the process of exploration if fully automatic driving is achieved
at the beginning, we were worried about what passengers would think about automatic driving, whether our technology could bring good experience to passengers, and whether passengers would like to ride in a car controlled by a machine. Now we have the answer, 93% of the customers think there is no problem, and more and more passengers. In other words, we have gained a lot of experience in terms of market model and future customer trend. Of course, we have accumulated some technical data, which is priceless. For example, in Las Vegas, our self driving taxis can run to the airport and any hotel. During this period, we accumulated a lot of artificial intelligence data. The machine is learning every day, and the car is running better and better. This is the technical experience
and Hyundai are totally different ways of cooperation. We set up a joint venture to jointly develop automatic driving. With the development and change of the instrial chain, the roles of OEM and us are changing. The cooperation with Hyundai is a typical example. How can a system supplier and OEM cooperate to achieve the goal of autonomous driving and other future travel? In addition to the current co funded cooperation, it is also very important who will test the automatic driving platform. Hyundai has a complete vehicle platform. If we test the new electronic and electrical architecture, Hyundai will be in a very favorable position and can create a platform for us in the future like a piece of white paper
the cooperation with Hyundai has just begun, and both sides are also exploring the cooperation mode of tier 1 and OEM at the level of automatic driving, what kind of effect will it proce in the new market and new business field, who will do what at that time, and it is necessary for both sides to benefit each other and occupy a certain position in the future travel market. This will bring us very important experience in cooperation
the instry is not in constant cold.
Q: today's auto market is in a downward trend as a whole. On the one hand, auto enterprises need to rece costs, on the other hand, they need to invest a lot of money to research forward-looking technologies that have not yet been implemented. How do you think to find a balance between the two<
Yang Xiaoming: China's auto market is a special situation. It has been growing in the past few decades. However, foreign countries have experienced several rounds of cyclical process. We can see that it is not realistic to achieve long-term stable growth
strictly speaking, this company has just turned 2 years old
on December 5, 2017, after Delphi split its powertrain business, Delphi officially unveiled its new company name, APTIV PLC, and announced that it focused on accelerating the commercialization process in the fields of active safety, automatic driving, improving driving experience and Internet services
in other words, Delphi, a traditional auto parts manufacturer, intends to devote a considerable part of its energy to the "brain" and "nervous system" of cars, such as the software, algorithms, and car architecture needed for automatic driving
according to the official statement, in the four or five years since the company first entered the field of automatic driving, everything has gone smoothly:
in 2015, amber Ford completed the automatic driving test across the mainland of the United States, becoming the first company in the world to launch the commercial project of automatic driving
in May 2018, amber and LYFT cooperated to launch the commercial operation project of automatic driving, and launched the public oriented automatic driving network car Hailing service in Las Vegas
as of September 2019, the company has provided more than 70000 person times of automatic driving network car Hailing service and obtained a passenger satisfaction score of 4.95 (full score of 5). At present, commercial development projects of automatic driving have been carried out in Las Vegas, Boston and Singapore
naturally, amber has graally extended its tentacles to the research and development of L4 automatic driving. At this time, the team found that in order to achieve high-level automatic driving and mass proction, the current automotive infrastructure is far from meeting the demand
so Yang Xiaoming, President of Asia Pacific region, shared his own design concept. At the same time, he also discussed with Che Yunjun the feasible business model in the future and the prospect of the automatic driving instry -
the birth of a new supply relationship
Q: please give us a brief introction of the new generation infrastructure of amber, and what stage has the cooperation reached at present
Yang Xiaoming: at present, the traditional way of automobile architecture design is nearly saturated, and the architecture design must go to the next generation, innovation and reform
the direction of electric vehicles has been proved, especially in the Chinese market. Tesla's success has proved that pure electric vehicles are the development direction. The application speed of the new architecture on electric vehicles may be faster, because it is relatively simple, and there is no complex powertrain mole such as traditional fuel vehicle powertrain
at present, our procts have appeared in CES 2020, and are no longer in the stage of concept. At the same time, such innovative and revolutionary ideas and procts can not be put in place in one step. Now many ideas have begun to be promoted in the current new projects and applied locally, including the graal rection of moles in some customer models and the graal change to the direction of domain control
Q: as far as I know, many manufacturers are studying the domain controller. When will the procts of anbofu be launched
Yang Xiaoming: in this year's CES, we have exhibited a comprehensive range of procts, including domain controllers, computing control centers, etc. We are discussing with some customers, including traditional vehicle manufacturers and new force car manufacturers. There will be some conflicts between new technology and previous procts at the design level. The new technology has a characteristic that its cycle is much faster than the traditional car development in previous years, so the time is very short. And the Chinese market also has a characteristic, local enterprises to accept new technologies, new concepts quickly, once it will move quickly
Q: when this architecture is implemented in mass proction, what requirements will it put forward for chip and computing power modification
Yang Xiaoming: higher requirements are required for chips, but the cost of chips is not a problem at present, because the technology is developing very fast, and the most important problem is the system. The control system of anbofo is based on an open architecture, which avoids the difficulties caused by the lack of unified standards in the future. So the chip is definitely upgrading. The function of the chip is much faster and bigger than that of the previous ECU chip, but the most important thing is an open operation system, OS system
as far as the auto driving scheme is concerned, there are two major directions for discussion. One is to put all the computing power on the sensors and cameras. At present, many vehicle applications do this. But it will face a very big problem. In case of equipment failure, the maintenance cost will be very high. Take the sensor as an example, now every sensor has a chip, and the cost of maintenance is very high
the other direction is the route of sensor fusion, which sends the processing and information to the central area block and the computing center for processing. At present, this may be a feasible direction, but it still needs an evolutionary process
Q: what are the differences between domestic and foreign electronic and electrical architecture systems? Are there any differences? Does China's architecture also need to adapt to localization standards<
Yang Xiaoming: there is no regional difference in the electronic and electrical architecture, but China certainly has its particularity. From the perspective of architecture, we don't think there are big differences in architecture. There may be slight differences in the requirements of laws and regulations in different countries
reporter: the logic of the evolution of electronic and electrical architecture of many auto companies is to transform to the software level. How to balance the contradiction between suppliers and OEMs
Yang Xiaoming: This is not a contradiction, but a new model and the instrial chain reform it brings. In the process of building a new instrial chain, we must quickly define which end of the instrial chain we are at, which is very critical. For example, we are a system supplier. Many of our advantages lie in the calculation of hardware and software. We also do many ECU programs, and we are also doing software
in the end, the purpose of OEM software will be different from ours, because we are controlling cars, and their software will focus more on the needs of end customers: what kind of applications do car owners need? They want to make the end customer experience and customer demand software very well, and the profits brought by software are unimaginable
the future business model of autonomous driving
Yang Xiaoming: we have 75 vehicles in operation in Las Vegas, which are completely running every day. Passengers can call the self driving taxi of anbofu through the taxi software. So it's completely commercial operation, not a demonstration. We've passed this stage
recently, the scope of operation has been extended to the airport, which is of great significance to the operation of self driving shared car, because in the past, the airport was not unable to do it, but the security inspection had a lot of worries about self driving, and the whole approval process was relatively long. By the end of last year, there had been 70000 times of driving, and the growth rate was very fast. The performance of automatic driving was also very smooth and safe. Nine out of 10 passengers said that they would choose our automatic driving taxi again
in recent years, the instry has been discussing how to expand the business model of automatic driving. Nowadays, the same situation is also faced in China. You can't rely on the government forever. It can't achieve sustainable development. So we chose to work with LYFT to explore a sustainable business model. There are many applicable scenarios in China, which are easier than those in foreign countries
now practitioners are flocking to research algorithms and AI. I think the more important thing is how to find a successful business model, what role the host plant should play, what role the system supplier should play, and what role the software supplier should play
secondly, we have been calling for the government's laws and regulations to be kept up with, and the laws and regulations should be focused on. I feel that the domestic government is often in a passive mode of response and is often forced to come up with a special way to grant a piece of land and open up an area. Las Vegas, for example, has a certain legal support. The legal advisers of the state government meet with enterprises regularly. In particular, autonomous driving companies like us have a meeting to discuss what problems will arise in the future, what problems are unclear at the present legal level, and how to match laws and regulations. This is worth learning in China. Otherwise, only a few dozen or a few hundred of them will be able to work out the commercial environment of automatic driving
Q: in the cooperation with LYFT and Hyundai Auto, what is the business model that amberful explored
Yang Xiaoming: These are two different kinds of cooperation. They are the cooperation with LYFT for the commercial landing of automatic driving, and they launch automatic driving on the shared travel platform. Shared travel will occupy a large proportion in the future mobile travel business. At the same time, how to use the idle period of vehicles is in the process of exploration if fully automatic driving is achieved
at the beginning, we were worried about what passengers would think about automatic driving, whether our technology could bring good experience to passengers, and whether passengers would like to ride in a car controlled by a machine. Now we have the answer, 93% of the customers think there is no problem, and more and more passengers. In other words, we have gained a lot of experience in terms of market model and future customer trend. Of course, we have accumulated some technical data, which is priceless. For example, in Las Vegas, our self driving taxis can run to the airport and any hotel. During this period, we accumulated a lot of artificial intelligence data. The machine is learning every day, and the car is running better and better. This is the technical experience
and Hyundai are totally different ways of cooperation. We set up a joint venture to jointly develop automatic driving. With the development and change of the instrial chain, the roles of OEM and us are changing. The cooperation with Hyundai is a typical example. How can a system supplier and OEM cooperate to achieve the goal of autonomous driving and other future travel? In addition to the current co funded cooperation, it is also very important who will test the automatic driving platform. Hyundai has a complete vehicle platform. If we test the new electronic and electrical architecture, Hyundai will be in a very favorable position and can create a platform for us in the future like a piece of white paper
the cooperation with Hyundai has just begun, and both sides are also exploring the cooperation mode of tier 1 and OEM at the level of automatic driving, what kind of effect will it proce in the new market and new business field, who will do what at that time, and it is necessary for both sides to benefit each other and occupy a certain position in the future travel market. This will bring us very important experience in cooperation
the instry is not in constant cold.
Q: today's auto market is in a downward trend as a whole. On the one hand, auto enterprises need to rece costs, on the other hand, they need to invest a lot of money to research forward-looking technologies that have not yet been implemented. How do you think to find a balance between the two<
Yang Xiaoming: China's auto market is a special situation. It has been growing in the past few decades. However, foreign countries have experienced several rounds of cyclical process. We can see that it is not realistic to achieve long-term stable growth
6. Computing can be seen everywhere in life, and it is a tool to help people solve problems. In primary school, computing teaching runs through the whole process of mathematics teaching, and it is the basic knowledge and basic skills that primary school students need to master in learning mathematics. It is one of the main tasks of primary school mathematics to cultivate and improve students' computing ability. It is a systematic project involving many aspects of teaching content. The proportion of "calculation" in teaching is quite large. Whether it is applied problems, statistical knowledge, geometric problems and simple equations, it is inseparable from calculation. The accuracy and speed of calculation will directly affect the quality of students' learning, so the teaching of calculation can not be ignored. Computing teaching should be out of the frame of cognitive skills, not the rule, the formation of skills as the only goal, but should pay more attention to the students' learning process, let the students participate in the process of exploration of computing algorithm, let the students in the process of practice and exploration to achieve the development of domain goals. In my teaching, the implementation of classified guidance, strengthen training, step by step, from improving the ability of oral calculation to improve the accuracy of calculation, there are some superficial understanding
first, create situations to stimulate interest
"interest is the best teacher". I think teachers should create certain teaching situations to let students explore new knowledge with a strong thirst for knowledge. Make the dry calculation teaching lively and interesting, set up students' self-confidence, and make them willing to learn and do. In order to arouse students' interest, we should explain some typical examples of Chinese and foreign mathematicians or stories related to classroom teaching. For example: before teaching simple operation, I first explained to the students the story of the mathematician Gauss's creative answer to the sum of 100 natural numbers "1 + 2 + 3 +... + 99 + 100", which created a good learning situation for the students and stimulated their interest in learning mathematics. The students unconsciously had the idea of comparing with the mathematicians. As a result, the students are more careful than before in examining the questions, analyzing the characteristics of the questions more carefully than before, and can flexibly use the relevant laws and rules to find out the rules of doing the questions< Second, guide students in all directions and train them reasonably. For example, when I teach how to multiply three digits by two digits, I first let the students master the calculation method of multiplying three digits by two digits, which is consistent with the calculation method of multiplying two digits by two digits. The difference is that the pull number of a factor changes from two digits to three digits. On the basis of fully considering students' existing knowledge and experience and cognitive development level, I actively guide students to transfer old knowledge to new knowledge. I want the students to have a try by themselves. On the basis of active exploration, cooperation and communication, I want them to further understand the calculation principle of integer multiplication, so as to master the calculation method of multiplying three digits by two digits and use it to solve simple problems
2. Let students fully "speak" and combine operation with language. Change the past calculation teaching is the students' calculation method, let the students give full play to the "say", say their own thinking process, and give appropriate guidance, give students a good way of thinking. At the same time, teachers and students should pay attention to the role of demonstration operation, and combine operation with language. Strengthen students' intuitive understanding and effectively develop students' thinking
3. Strengthen the training of estimation and cultivate students' sense of number. By using the estimation method, the calculation results can be positioned in advance, and the value range of the calculation results can be determined quickly. Through the estimation before calculation and the check after calculation, the errors caused by carelessness can be avoided. Let the students look at the last digit of the result. If the indivial digits are 3 and 8, the sum of the indivial digits of the result must be 1, and the multiplication must be 4, such as 13 × The 26 proct can't be two digits, etc
4. Reasonable training. Design various forms of exercises to improve students' interest in learning calculation. In order to cultivate and improve students' computing ability, we must be able to achieve the goal through continuous and a lot of practice. If we let students do a lot of monotonous computing practice repeatedly, students are easy to get tired and can't get the expected effect. Therefore, I designed a variety of forms, flexible, both targeted, knowledgeable, and interesting exercises to stimulate students' interest in learning and encourage each student to actively participate
(1) practice every day. Use morning self-study every day to strengthen students' calculation training. The calculation of indivial items should be focused on according to the students' mastery, and the difficult and error prone parts should be focused on
(2) contrast exercises. In my teaching, I put the easy to mix and easy to make mistakes together, let the students distinguish and compare, through purposeful practice, make the students correct the mistakes, so as to improve the students' ability of discrimination, and evaluate the students' homework in time to correct the mistakes
(3) error correction exercises. I deliberately wrote out the typical mistakes in the students' homework on the blackboard, let the students point out the mistakes, explain the causes of the mistakes, and correct them. Regularly have a class to correct mistakes, let students be "wrong doctor" to suit the remedy to the case< Third, to overcome carelessness and cultivate habits
from the phenomenon, it seems that most of the students' calculation errors are caused by "carelessness", and the reasons for "carelessness" are no more than two aspects: one is that children's physical and psychological development is not mature enough, the other is that they have not formed good learning habits. The cultivation of good study habits is concive to the development of body and mind. The good habits you have developed since childhood will benefit you for a lifetime. Therefore, cultivating students' good study habits is not only the requirement of quality ecation, but also the premise of improving the accuracy of calculation. Students have the following common mistakes: reading wrong, ing wrong topic; When the column is vertical, the digits are not aligned; There is no draft in calculation; The calculation error of one digit addition and subtraction leads to the error of the whole question; I don't concentrate on my homework. According to the analysis of the causes of students' calculation errors, a considerable part of the factors are the problems of learning habits. Therefore, to cultivate good learning habits is to prevent calculation errors and let students form the habit of checking after ing; At the end of calculation, the habit of fast checking calculation with estimation method, and the habit of looking back combined with the topic meaning, etc. are all important ways to improve the quality of practice
1. Develop a good habit of examining questions
in teaching, I put forward strict requirements for students, asking them to calculate carefully. In addition, I also give students some methods. For example: Calculation of the inspection method, I summed up the following: a pair of questions, two pairs of vertical, three pairs of calculation, four pairs of number. The way to examine the topic is to see and think twice. That is: first look at the whole formula, which is composed of several parts, and think about how to calculate according to the general rules; Let's see if there are any special conditions. Let's see if we can use a simple method to calculate. If students do it according to these methods, the calculation will have a preliminary guarantee
2, develop good writing habits
there are obvious differences in the attitude of students in the class, some students even write nonstandard, often write "3" as "5", "1" as "7" and so on, I will let them to practice calligraphy and other means to make their writing as "understandable" as far as possible, so as to avoid ing wrong questions
3. Develop a good habit of inspection
to cultivate students' good habit of calculation, do oral calculation as much as possible if they can, and use straw paper for vertical calculation if they can't, and develop a good habit of inspection. In order to let students know the test method, we can generally use the relationship of four mixed operations to test. We can also flexibly use some test methods, such as the test of equation, we can use the substitution method
when cultivating students' good calculation habits, teachers should be patient and persistent, unify methods and requirements, persevere and grasp them to the end< In a word, improving students' computing ability is a meticulous and long-term teaching work. To develop a good habit of calculation, in order to improve students' calculation ability.
first, create situations to stimulate interest
"interest is the best teacher". I think teachers should create certain teaching situations to let students explore new knowledge with a strong thirst for knowledge. Make the dry calculation teaching lively and interesting, set up students' self-confidence, and make them willing to learn and do. In order to arouse students' interest, we should explain some typical examples of Chinese and foreign mathematicians or stories related to classroom teaching. For example: before teaching simple operation, I first explained to the students the story of the mathematician Gauss's creative answer to the sum of 100 natural numbers "1 + 2 + 3 +... + 99 + 100", which created a good learning situation for the students and stimulated their interest in learning mathematics. The students unconsciously had the idea of comparing with the mathematicians. As a result, the students are more careful than before in examining the questions, analyzing the characteristics of the questions more carefully than before, and can flexibly use the relevant laws and rules to find out the rules of doing the questions< Second, guide students in all directions and train them reasonably. For example, when I teach how to multiply three digits by two digits, I first let the students master the calculation method of multiplying three digits by two digits, which is consistent with the calculation method of multiplying two digits by two digits. The difference is that the pull number of a factor changes from two digits to three digits. On the basis of fully considering students' existing knowledge and experience and cognitive development level, I actively guide students to transfer old knowledge to new knowledge. I want the students to have a try by themselves. On the basis of active exploration, cooperation and communication, I want them to further understand the calculation principle of integer multiplication, so as to master the calculation method of multiplying three digits by two digits and use it to solve simple problems
2. Let students fully "speak" and combine operation with language. Change the past calculation teaching is the students' calculation method, let the students give full play to the "say", say their own thinking process, and give appropriate guidance, give students a good way of thinking. At the same time, teachers and students should pay attention to the role of demonstration operation, and combine operation with language. Strengthen students' intuitive understanding and effectively develop students' thinking
3. Strengthen the training of estimation and cultivate students' sense of number. By using the estimation method, the calculation results can be positioned in advance, and the value range of the calculation results can be determined quickly. Through the estimation before calculation and the check after calculation, the errors caused by carelessness can be avoided. Let the students look at the last digit of the result. If the indivial digits are 3 and 8, the sum of the indivial digits of the result must be 1, and the multiplication must be 4, such as 13 × The 26 proct can't be two digits, etc
4. Reasonable training. Design various forms of exercises to improve students' interest in learning calculation. In order to cultivate and improve students' computing ability, we must be able to achieve the goal through continuous and a lot of practice. If we let students do a lot of monotonous computing practice repeatedly, students are easy to get tired and can't get the expected effect. Therefore, I designed a variety of forms, flexible, both targeted, knowledgeable, and interesting exercises to stimulate students' interest in learning and encourage each student to actively participate
(1) practice every day. Use morning self-study every day to strengthen students' calculation training. The calculation of indivial items should be focused on according to the students' mastery, and the difficult and error prone parts should be focused on
(2) contrast exercises. In my teaching, I put the easy to mix and easy to make mistakes together, let the students distinguish and compare, through purposeful practice, make the students correct the mistakes, so as to improve the students' ability of discrimination, and evaluate the students' homework in time to correct the mistakes
(3) error correction exercises. I deliberately wrote out the typical mistakes in the students' homework on the blackboard, let the students point out the mistakes, explain the causes of the mistakes, and correct them. Regularly have a class to correct mistakes, let students be "wrong doctor" to suit the remedy to the case< Third, to overcome carelessness and cultivate habits
from the phenomenon, it seems that most of the students' calculation errors are caused by "carelessness", and the reasons for "carelessness" are no more than two aspects: one is that children's physical and psychological development is not mature enough, the other is that they have not formed good learning habits. The cultivation of good study habits is concive to the development of body and mind. The good habits you have developed since childhood will benefit you for a lifetime. Therefore, cultivating students' good study habits is not only the requirement of quality ecation, but also the premise of improving the accuracy of calculation. Students have the following common mistakes: reading wrong, ing wrong topic; When the column is vertical, the digits are not aligned; There is no draft in calculation; The calculation error of one digit addition and subtraction leads to the error of the whole question; I don't concentrate on my homework. According to the analysis of the causes of students' calculation errors, a considerable part of the factors are the problems of learning habits. Therefore, to cultivate good learning habits is to prevent calculation errors and let students form the habit of checking after ing; At the end of calculation, the habit of fast checking calculation with estimation method, and the habit of looking back combined with the topic meaning, etc. are all important ways to improve the quality of practice
1. Develop a good habit of examining questions
in teaching, I put forward strict requirements for students, asking them to calculate carefully. In addition, I also give students some methods. For example: Calculation of the inspection method, I summed up the following: a pair of questions, two pairs of vertical, three pairs of calculation, four pairs of number. The way to examine the topic is to see and think twice. That is: first look at the whole formula, which is composed of several parts, and think about how to calculate according to the general rules; Let's see if there are any special conditions. Let's see if we can use a simple method to calculate. If students do it according to these methods, the calculation will have a preliminary guarantee
2, develop good writing habits
there are obvious differences in the attitude of students in the class, some students even write nonstandard, often write "3" as "5", "1" as "7" and so on, I will let them to practice calligraphy and other means to make their writing as "understandable" as far as possible, so as to avoid ing wrong questions
3. Develop a good habit of inspection
to cultivate students' good habit of calculation, do oral calculation as much as possible if they can, and use straw paper for vertical calculation if they can't, and develop a good habit of inspection. In order to let students know the test method, we can generally use the relationship of four mixed operations to test. We can also flexibly use some test methods, such as the test of equation, we can use the substitution method
when cultivating students' good calculation habits, teachers should be patient and persistent, unify methods and requirements, persevere and grasp them to the end< In a word, improving students' computing ability is a meticulous and long-term teaching work. To develop a good habit of calculation, in order to improve students' calculation ability.
7. 1、 To cultivate lower grade students to develop good calculation habits will directly affect the formation and improvement of students' calculation ability. Many students can understand and master the algorithm, but they often make mistakes, mainly e to the lack of strict training and good learning habits. In order to improve students' computing ability, we must pay attention to the cultivation of good computing habits. 1. Make students form the habit of examining questions. Students are required to see each data and operation symbol clearly, determine the operation order, and choose a reasonable operation method. 2. Make students form the habit of careful calculation and standard writing. Students are required to write neatly and the writing format should be standardized. At the same time, those who can do oral arithmetic should do oral arithmetic, while those who can't should do written arithmetic seriously, so as to strengthen the students' habit of standardized drafting. In column vertical calculation, the number of digits should be aligned, there should be an appropriate interval between the numbers, the carry number should be written in an appropriate position, and the number of exit points should not be less. 3. Make students form the habit of estimation and self-conscious checking. Teachers should teach students the methods of checking and estimating, and make strict demands on checking as an important part of the calculation process. It is advocated to use estimating to check the correctness of the answers< Second, to seek the balance between calculation theory and algorithm
the traditional calculation teaching only pays attention to the calculation results, neglects the derivation of calculation theory, and students' learning only stays at the level of correct calculation and fast calculation. At the beginning of the curriculum reform, the teaching of calculation has turned to the other extreme. It attaches great importance to how you calculate and how you can calculate. However, it lacks the refinement of the calculation method, which leads to the outstanding calculation theory, the algorithm is not solid, and the students' calculation skills are not proficient. So how to find the balance between theory and algorithm? In order to make students know how to calculate, we must first make students know how to calculate, that is, strengthen the understanding of the rules and calculation theory. In teaching, the teacher should guide the students to understand the calculation theory with clear theory, and master the calculation method on the basis of understanding the calculation theory, which is just the so-called "knowing what it is and why it is"< Third, strengthen the training of oral arithmetic ability
to cultivate students' computational ability, we should pay attention to the basic training of oral arithmetic, which is not only the basis of written calculation, estimation and simple calculation, but also an important part of computational ability. Only when the ability of oral calculation is strong, can the speed of written calculation be accelerated and the accuracy of calculation be improved. Teachers should print and print a mental arithmetic book according to the combination of teaching materials and students' reality, and make full use of this book. The teaching content of lower grades is relatively less. Teachers can time the children in class and let them do it. At this time, students' attention is very focused, and students' calculation speed will be improved effectively. Oral arithmetic is not only to time, more important is to give children to see right and wrong, for those who can get full marks in the prescribed time to give a certain reward in time, cause students to pay attention to oral arithmetic, in addition to pay attention to oral arithmetic is a must do homework, usually adhere to such a work. Only in this way can we improve the ability of oral arithmetic< Fourth, carry out competitions to stimulate students' interest in learning
motivation is the subjective reason to motivate people to take action. The stronger the students' motivation, the more they can show strong interest in learning, and then turn it into an internal driving force of learning. Therefore, in the teaching of calculation problems, we should try every means to make students have strong interest and curiosity in calculation problems, Guide and encourage them to participate in new and interesting exploratory learning activities. Purposely design and arrange some competition forms of exercises and mathematical games to stimulate students' interest in learning, so that the whole class can actively participate. The forms of competition are: winning the red flag, mathematics relay race, rushing to answer, etc“ The competition of "winning the red flag" is to draw a mountain on the blackboard. There are three roads on the mountain, and each road has five arithmetic problems. 15 "mountaineers" are selected and divided into three groups. Each group is divided into three groups, one for each. The first group who completes the competition and all for each other can win a small red flag“ "Mathematics relay race", that is, each group has a problem, each person does a problem and then pass it down, the last person in each group finish it, hand it in, and then evaluate it in the class. The group that does it all right and fast wins. Such a competition can not only arouse students' desire for knowledge and tap their potential, but also enhance students' enterprising spirit and collective sense of honor, so that students can learn in a happy atmosphere< 5. Pay attention to the analysis of wrong questions. Students' learning is a process of repeated understanding and practice, and mistakes are inevitable. Especially for the younger students, the knowledge they just learned is easy to forget. For example, if the abdication is subtracted, the previous digit is subtracted by 1, and you forget to subtract 1 when calculating. Similarly, when you do carry plus time, you forget to carry. In particular, the addition of continuous carry, subtraction of continuous abdication, forgetting to add or omitting to write are more errors, which are related to children's incomplete memory. Therefore, teachers should timely understand the problems existing in students' calculation, deeply analyze the causes of their calculation errors, and carry out targeted teaching. Let the students know the reason of the mistake, because of their carelessness, or which aspect of the knowledge is not good enough, know the mistake again, to deepen the understanding of the correct knowledge. Teachers should focus on the analysis of the reasons for the wrong questions according to the person and the topic. Most students have done the wrong questions, so teachers should focus on explaining and analyzing the reasons for the mistakes; For students with poor foundation and often making mistakes, teachers should spend more time in tutoring after class. Students should reflect on the mistakes in their homework. Each student should prepare a book, write down the mistakes in the daily homework in the book, and write down the mistakes and correction methods. In addition, we should take the similar questions that students often make mistakes as the students' homework, and feedback again to understand the homework effect after students correct their mistakes. The practice of correcting wrong questions requires students to judge right and wrong, find out the mistakes, analyze the causes of mistakes, and correct them. The class adopts the form of a little doctor to find the cause of disease competition, so that students can acquire knowledge in the competition“ "Correcting mistakes" can not only satisfy students to distinguish the causes of mistakes and correct them, but also achieve the effect of prevention.
the traditional calculation teaching only pays attention to the calculation results, neglects the derivation of calculation theory, and students' learning only stays at the level of correct calculation and fast calculation. At the beginning of the curriculum reform, the teaching of calculation has turned to the other extreme. It attaches great importance to how you calculate and how you can calculate. However, it lacks the refinement of the calculation method, which leads to the outstanding calculation theory, the algorithm is not solid, and the students' calculation skills are not proficient. So how to find the balance between theory and algorithm? In order to make students know how to calculate, we must first make students know how to calculate, that is, strengthen the understanding of the rules and calculation theory. In teaching, the teacher should guide the students to understand the calculation theory with clear theory, and master the calculation method on the basis of understanding the calculation theory, which is just the so-called "knowing what it is and why it is"< Third, strengthen the training of oral arithmetic ability
to cultivate students' computational ability, we should pay attention to the basic training of oral arithmetic, which is not only the basis of written calculation, estimation and simple calculation, but also an important part of computational ability. Only when the ability of oral calculation is strong, can the speed of written calculation be accelerated and the accuracy of calculation be improved. Teachers should print and print a mental arithmetic book according to the combination of teaching materials and students' reality, and make full use of this book. The teaching content of lower grades is relatively less. Teachers can time the children in class and let them do it. At this time, students' attention is very focused, and students' calculation speed will be improved effectively. Oral arithmetic is not only to time, more important is to give children to see right and wrong, for those who can get full marks in the prescribed time to give a certain reward in time, cause students to pay attention to oral arithmetic, in addition to pay attention to oral arithmetic is a must do homework, usually adhere to such a work. Only in this way can we improve the ability of oral arithmetic< Fourth, carry out competitions to stimulate students' interest in learning
motivation is the subjective reason to motivate people to take action. The stronger the students' motivation, the more they can show strong interest in learning, and then turn it into an internal driving force of learning. Therefore, in the teaching of calculation problems, we should try every means to make students have strong interest and curiosity in calculation problems, Guide and encourage them to participate in new and interesting exploratory learning activities. Purposely design and arrange some competition forms of exercises and mathematical games to stimulate students' interest in learning, so that the whole class can actively participate. The forms of competition are: winning the red flag, mathematics relay race, rushing to answer, etc“ The competition of "winning the red flag" is to draw a mountain on the blackboard. There are three roads on the mountain, and each road has five arithmetic problems. 15 "mountaineers" are selected and divided into three groups. Each group is divided into three groups, one for each. The first group who completes the competition and all for each other can win a small red flag“ "Mathematics relay race", that is, each group has a problem, each person does a problem and then pass it down, the last person in each group finish it, hand it in, and then evaluate it in the class. The group that does it all right and fast wins. Such a competition can not only arouse students' desire for knowledge and tap their potential, but also enhance students' enterprising spirit and collective sense of honor, so that students can learn in a happy atmosphere< 5. Pay attention to the analysis of wrong questions. Students' learning is a process of repeated understanding and practice, and mistakes are inevitable. Especially for the younger students, the knowledge they just learned is easy to forget. For example, if the abdication is subtracted, the previous digit is subtracted by 1, and you forget to subtract 1 when calculating. Similarly, when you do carry plus time, you forget to carry. In particular, the addition of continuous carry, subtraction of continuous abdication, forgetting to add or omitting to write are more errors, which are related to children's incomplete memory. Therefore, teachers should timely understand the problems existing in students' calculation, deeply analyze the causes of their calculation errors, and carry out targeted teaching. Let the students know the reason of the mistake, because of their carelessness, or which aspect of the knowledge is not good enough, know the mistake again, to deepen the understanding of the correct knowledge. Teachers should focus on the analysis of the reasons for the wrong questions according to the person and the topic. Most students have done the wrong questions, so teachers should focus on explaining and analyzing the reasons for the mistakes; For students with poor foundation and often making mistakes, teachers should spend more time in tutoring after class. Students should reflect on the mistakes in their homework. Each student should prepare a book, write down the mistakes in the daily homework in the book, and write down the mistakes and correction methods. In addition, we should take the similar questions that students often make mistakes as the students' homework, and feedback again to understand the homework effect after students correct their mistakes. The practice of correcting wrong questions requires students to judge right and wrong, find out the mistakes, analyze the causes of mistakes, and correct them. The class adopts the form of a little doctor to find the cause of disease competition, so that students can acquire knowledge in the competition“ "Correcting mistakes" can not only satisfy students to distinguish the causes of mistakes and correct them, but also achieve the effect of prevention.
8. Due to the graal popularization of computing tools, the requirements of social life for computing skills are graally reced, and the requirements of primary school textbooks for computing ability are also reced. But the process of computing teaching is a process of cultivating students' thinking. The improvement of computing ability can promote the development of students' thinking ability. So how can we improve students' computing ability< In order to make students know how to calculate, it is necessary for them to know how to calculate, that is, to master the rules and calculation principles "Curriculum standard" points out: "in teaching, we should further cultivate students' sense of number and enhance their understanding of the meaning of operation by solving problems." Therefore, in the teaching, we should combine with the practical problems to understand the calculation theory and guide students to master the calculation method. Algorithm diversification is a highlight of mathematics curriculum reform and a difficulty in practice. Algorithm diversification encourages students to think independently, encourage students to think diversified, encourage students to solve problems indivialized, and pursue the development of students indivialized, which is based on the development and improvement of students. Only let students think independently, explore the algorithm in cooperation and communication, and graally optimize the algorithm. For example, when teaching cinema, Volume 2, grade 3, Beijing Normal University Edition, let the students analyze the questions and list the formula 26 × 21 Two digit multiplication has been learned, this problem is just more carry, so in the teaching, I let the students solve it independently, and exchange the calculation method in the group< Second, strengthen the training of students' oral arithmetic. Oral arithmetic is the basis of written arithmetic, and the formation of written arithmetic skills is directly restricted by the accuracy and proficiency of oral arithmetic. Therefore, it is necessary to strengthen the teaching and training of oral arithmetic and lay a solid foundation for it. In order to improve students' oral arithmetic ability and form certain skills, the key is to persevere and persist in training. Therefore, I will strengthen students' oral arithmetic training from the following two aspects
1. In teaching, I asked students to write 12 oral arithmetic questions in class, and those who did well were rated as "stars of oral arithmetic". Due to the different levels of students, there are various types of questions, and because the questions are given by students themselves, students are more active in doing the questions, and the classroom atmosphere is active. Finally, the feedback is given by driving a train
2. Three students in a group, one student questions, one student to say the number, there is a student when the referee and use their favorite statistical method to count the outcome of the game. Such games not only make students happy to learn, love to learn, but also bring the games to extracurricular with classmates to do, take home with dad and mom to do< Third, we should pay attention to the cultivation of students' estimation ability. Estimation is an important link to ensure the accuracy of calculation and an important means to improve the calculation ability. The system estimates before calculation, which can estimate the approximate value range of the number and create conditions for the accuracy of calculation. For example: in the teaching of "sorting out schoolbags", first show the theme map. A bookshelf has 12 layers, 14 books on each layer. Can 150 books be put down? Let the students estimate independently and give feedback collectively. ①、14 × 10 = 140 (this) ②, 15 × 10 = 150 (Ben) of course, estimation can only find obvious errors in calculation, and can not replace calculation and checking. Only by combining estimation, calculation and checking, can we ensure correct calculation, quickly and comprehensively improve students' calculation level and ability. So then ask the students to find out how many books this shelf can hold? The results are compared and verified with the estimated results
another example: when teaching Beijing Normal University Edition fourth grade volume I "stadium", show the teaching wall map for students to estimate the number of audience? Most students feel very difficult to see the title, "teacher, how do we estimate the dense people?" The students seem to be at a loss. Therefore, in teaching, I first let students think independently and then give full play to their leading role. Let them talk about their estimation methods and estimated results in the group, and then the group will send representatives to feed back and exchange the results< Student 1: it can be seen from the picture that there are about 50 seats in each small grandstand. This stadium may have 30 grandstands, about 1500 seats< Student 2: the number of seats in each row of the stadium is about 200. It is estimated that the stadium has 20 rows, with a total of about 4000 seats< Student 3: divide the stadium into four directions: East, West, South and North, with about 1000 people sitting in each direction and about 4000 people sitting in four directions
all these estimation methods are reasonable. They should be affirmed and praised for their teaching adaptation, so as to make students happy to try and succeed. In the study of this estimation method, it is explored that many students can test three digit by two digit and further study three digit by two digit to provide the basis, and promote the development of students' judgment, reasoning and other multi-directional thinking< Fourth, cultivate students' good study habits
cultivate students' habit of serious examination. It is the main way and measure to prevent calculation error and improve calculation level to see operation symbols clearly and form good study habits
1. See the operation symbol clearly, see the number clearly, make clear the operation order. For example: 12 as 21, 2 as 5, 3 as 8, etc< 2. Cultivate the habit of serious calculation. In the four operations, it is necessary to train students' calm and calm learning attitude. When encountering the calculation questions with large numbers and many steps, we should not be impatient, think calmly and calculate carefully. Even simple calculation problems should be careful. Don't act rashly. When calculating, the writing should be neat, the format should be standard and the method should be reasonable
3. It is impossible to ask students to be 100% correct in calculation. Therefore, in teaching, we should also ecate students to form a good habit of carefully checking the calculus after calculation, and take the test as an indispensable part of the calculation problem. The inspection should be patient and careful, and check step by step: check whether the numbers and budget symbols are copied wrong. 2. Check whether the calculation process and results are correct. At the same time, we should combine the teaching content to teach students appropriate checking methods, such as re algorithm, inverse algorithm, exchange adder multiplier and other checking methods.
1. In teaching, I asked students to write 12 oral arithmetic questions in class, and those who did well were rated as "stars of oral arithmetic". Due to the different levels of students, there are various types of questions, and because the questions are given by students themselves, students are more active in doing the questions, and the classroom atmosphere is active. Finally, the feedback is given by driving a train
2. Three students in a group, one student questions, one student to say the number, there is a student when the referee and use their favorite statistical method to count the outcome of the game. Such games not only make students happy to learn, love to learn, but also bring the games to extracurricular with classmates to do, take home with dad and mom to do< Third, we should pay attention to the cultivation of students' estimation ability. Estimation is an important link to ensure the accuracy of calculation and an important means to improve the calculation ability. The system estimates before calculation, which can estimate the approximate value range of the number and create conditions for the accuracy of calculation. For example: in the teaching of "sorting out schoolbags", first show the theme map. A bookshelf has 12 layers, 14 books on each layer. Can 150 books be put down? Let the students estimate independently and give feedback collectively. ①、14 × 10 = 140 (this) ②, 15 × 10 = 150 (Ben) of course, estimation can only find obvious errors in calculation, and can not replace calculation and checking. Only by combining estimation, calculation and checking, can we ensure correct calculation, quickly and comprehensively improve students' calculation level and ability. So then ask the students to find out how many books this shelf can hold? The results are compared and verified with the estimated results
another example: when teaching Beijing Normal University Edition fourth grade volume I "stadium", show the teaching wall map for students to estimate the number of audience? Most students feel very difficult to see the title, "teacher, how do we estimate the dense people?" The students seem to be at a loss. Therefore, in teaching, I first let students think independently and then give full play to their leading role. Let them talk about their estimation methods and estimated results in the group, and then the group will send representatives to feed back and exchange the results< Student 1: it can be seen from the picture that there are about 50 seats in each small grandstand. This stadium may have 30 grandstands, about 1500 seats< Student 2: the number of seats in each row of the stadium is about 200. It is estimated that the stadium has 20 rows, with a total of about 4000 seats< Student 3: divide the stadium into four directions: East, West, South and North, with about 1000 people sitting in each direction and about 4000 people sitting in four directions
all these estimation methods are reasonable. They should be affirmed and praised for their teaching adaptation, so as to make students happy to try and succeed. In the study of this estimation method, it is explored that many students can test three digit by two digit and further study three digit by two digit to provide the basis, and promote the development of students' judgment, reasoning and other multi-directional thinking< Fourth, cultivate students' good study habits
cultivate students' habit of serious examination. It is the main way and measure to prevent calculation error and improve calculation level to see operation symbols clearly and form good study habits
1. See the operation symbol clearly, see the number clearly, make clear the operation order. For example: 12 as 21, 2 as 5, 3 as 8, etc< 2. Cultivate the habit of serious calculation. In the four operations, it is necessary to train students' calm and calm learning attitude. When encountering the calculation questions with large numbers and many steps, we should not be impatient, think calmly and calculate carefully. Even simple calculation problems should be careful. Don't act rashly. When calculating, the writing should be neat, the format should be standard and the method should be reasonable
3. It is impossible to ask students to be 100% correct in calculation. Therefore, in teaching, we should also ecate students to form a good habit of carefully checking the calculus after calculation, and take the test as an indispensable part of the calculation problem. The inspection should be patient and careful, and check step by step: check whether the numbers and budget symbols are copied wrong. 2. Check whether the calculation process and results are correct. At the same time, we should combine the teaching content to teach students appropriate checking methods, such as re algorithm, inverse algorithm, exchange adder multiplier and other checking methods.
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