Force table

1. Powerful computing power refers to the logical computing power of the processor and graphics and image processing power of the graphics card. Of course, it must be better, so a good CPU with a good graphics card with a good memory with a good host with a good power supply

2. Excel is more than 60000 lines at most, but more than 100000 lines have no response. Let's take an i7 and spend 6000 with a better one

3. 1. Open word, menu bar tools and find custom.
2. Click to open a tab, select command, select form in category, and find auto sum in command on the right. 3. Drag and drop it to an appropriate position in the common toolbar, and then close the custom dialog box
4. Now, put the insertion point in the cell where the sum is stored, and click the [auto sum] button in the common toolbar, then word will calculate and display the sum of the values in the upper cell or the left cell where the insertion point is located
5. What happens if there is data in the table above the insertion point
6. It will give priority to the summary of the data on the top and ignore the data in the table on the left.

4. The ratio increasing method and the equal difference increasing method are two methods to calculate the rent in the leasing business. According to its basic formula, we can dece and calculate that if the rent is calculated and paid according to the equal proportion increasing method, the actual rent rate will drop, or even drop by a large margin, resulting in the loss of the interests of the lessor; If the rent is calculated according to the equal difference increasing method, the actual rent rate is always equal to the nominal rent rate, and the calculation is simple. Therefore, the equal difference incremental method is more fair, reasonable and practical than the equal ratio incremental method

with the continuous deepening of China's middle school teaching reform, the Shanghai primary and secondary school mathematics curriculum standard (Trial draft) proposes to vigorously promote the digital mathematics activity (Dima) based on modern information technology, and establish the digital mathematics activity system based on computers and calculators (including scientific calculators Function calculator and graphic calculator) as the support, has intelligent software and rich courseware, connection information network Dima platform. Using this platform, we can improve the processing and presentation of mathematics content, and let students learn independently in the information technology environment, and carry out experiments, exploration and research

today, when we vigorously promote the universal application of information technology in the teaching process and promote the integration of information technology and subject curriculum, our school is also implementing the curriculum reform, and the graphic calculator is also applied to the classroom of mathematics expansion course. For this reason, we designed a teaching case of "using graphic calculator to study several methods of expressing arithmetic and proportional sequence"< Teaching background:

in the chapter of sequence, when explaining the concepts of arithmetic sequence and arithmetic sequence, the content is relatively simple and easy for students to master. It is the basis of learning sequence, which is helpful to cultivate students' observation ability and inction ability. The contents of the equal ratio sequence and the equal difference sequence are completely parallel, including the definition, the nature, the formula of the general term, the equal ratio (difference) median of two numbers, etc
after more than half a year of using graphic calculators, senior one students have a preliminary understanding of using graphic calculators to analyze, construct and explore mathematical problems. They felt that the use of graphic calculator not only changed their way of learning mathematics, but also increased their interest in learning mathematics. They like this "do math" way of learning very much

Graphic Calculator has many functions to use sequence, such as the use of general formula and recursive formula of sequence, sequence image and image tracking function, expression function of sequence operation table, iteration function of sequence, programming function of sequence, etc. All these have played a great role in learning the basic knowledge of sequence, correctly understanding sequence, making students experience the cognitive process of formula, understand the mathematical thinking method, and improve the ability of problem-solving in the effective attempt to guess, reasonable inction, simplified operation and verification operation< The design concept of the lesson is the core of the whole series knowledge learning. Conjecture, inction, recursion, analogy and other mathematical ideas are fully reflected in the learning of these two basic knowledge, which can be described as "although a sparrow is small, it has all five internal organs". However, it is difficult to fully and correctly show these in the traditional sequence teaching. This will lead to students' one-sided understanding of what they have learned, which will have a negative impact on the follow-up study of sequence. The graphic calculator has many functions to use the sequence, such as the use of the general formula and recursive formula, the image and image tracking function, the expression function of the operation table, the iteration function and the programming function of the sequence. All these have played a great role in learning the basic knowledge of sequence, correctly understanding sequence, making students experience the cognitive process of formula, understand the mathematical thinking method, and improve the ability of problem-solving in the effective attempt to guess, reasonable inction, simplified operation and verification operation. Therefore, we envisage that students can have a clear understanding of the two conventional series by studying and expressing the series with graphic calculator. At the same time, we also want to cultivate students' initiative and inquiry spirit and improve their mathematics learning ability through this learning process<

Design and Implementation:

the teaching content of the new textbook pays more attention to the integration of function thought and computer technology. From the beginning of this chapter, the textbook puts the number sequence in the context of function and gives the definition: the number sequence is a function with a positive integer set (or its finite subset) as the domain of definition. When the independent variable values in the order from small to large, the corresponding function value is the term of the number sequence. Sequence is a kind of discrete function. In the allocation of exercises, teaching materials are often compared with function teaching. The general term formula, recurrence formula and image of arithmetic sequence and proportional sequence are the main contents of our research in this lesson. We imagine that with the help of graphic calculator, we can make students have a vivid, comprehensive and correct understanding of sequence knowledge by doing mathematics, so as to improve students' mathematical thinking ability and cultivate students' correct mathematical view, Really improve students' interest in mathematics learning

case 1 (1) find the 11th term of the arithmetic sequence - 121, - 110, - 99, - 88,...

2) write the general term formula and recurrence formula of the sequence

for this problem, in fact, according to its basic law, you can calculate the result. But using graphic calculator can make us think about the solution of the problem from many angles, which is concive to students' comprehensive and correct understanding of the characteristics of arithmetic sequence, so as to simplify the calculation

method 1: use the numerical iteration function (as shown in Figure 1):

①

method 2: use the array function of the graphic calculator (as shown in Figure 2):

②

method 3: use the recursive function of the calculator

Figure 3: Use & iquest on the premise of setting the function function function; Key, which is the same as Figure 1< Method 4: guess the recurrence formula and the general term formula of the sequence, check whether the recurrence formula and the general term formula of the sequence are correct through the sequence related function of the calculator, and calculate the 11th term of the sequence:

Figure 4 guesses the recurrence formula of the sequence according to the characteristics of the sequence, Using the function of figure calculator, using Y & # 39; Draw a table

④

Fig. Then, we also use y & # 39; Draw a table< Note: while solving this problem, we can also verify that "the general term formula of arithmetic sequence is a special first-order function" through graphic calculator

as shown in Figure 7, we can get that the image of sequence is a discrete point on a straight line, from which we can see that sequence is a special function< Method 5: because the number sequence is a special function, we use the function of graphic calculator to think about the problem.

figure 8 is under the cognitive condition of "the number sequence is a special function", we use the function of calculator to get the function y = - 121 + 11 (x-1), and use the connection between the function and the number sequence an = - 121 + (n-1) to think about the related problems of the number sequence< Method 6: make full use of the function fitting function of the graphic calculator to get the general term formula of the sequence through the combination of number and shape

Figure 9: use the linear regression function of the graphic calculator to list the table of the sequence first, and then connect the general term formula of the arithmetic sequence with the first-order function according to the data in the table, By using the fitting function of graphic calculator, the function relation is obtained, and the general term formula of sequence is obtained< Method 7: use the programming function of graphic calculator to solve the problem of sequence (as shown in Figure 10)

10

comments: Method 1 and method 2 use the iterative function of calculator, but method 2 shows the corresponding relationship between the serial number and the value of the item in the sequence, from which we initially realize that the sequence is a special function

the fourth method is to guess the recurrence formula and general term formula of the sequence, under the support of the sequence function of the calculator, from the operation table of the sequence or the tracking of the image of the sequence to verify whether your guess is correct, and get the answer to the problem to be solved. This kind of learning method is helpful to cultivate students' ability of analysis, conjecture, demonstration and inction. This is what we lack in our regular learning, and the use of graphic calculator has built us such a learning method platform

method 6 and method 7 are both under the condition that the number sequence is a special function. Supported by the function function of the calculator, we find a way to solve the problem by guessing or fitting the analytic formula of the function, which is helpful for students to learn the knowledge of the number sequence and understand the characteristics of the number sequence, Method 8 adopts the programming function of graphic calculator, which can't be achieved in general mathematics teaching. It reveals the essence of arithmetic sequence from another perspective< (3) is 209 the item in the sequence, and if so, what is it< Method 1, array method 2, table method 3, image method 4, equation solving method the purpose of setting this question is: on the basis of the first question, using the functions of operation, tracking and equation solving of graphic calculator to cultivate students' reverse thinking and improve their mathematical thinking ability

it should be pointed out that the sequence we discussed above is tolerance D & gt; 0, for beginners, they often have certain thinking set, such as: "tolerance D & gt; In order to avoid similar problems, we especially remind students to pay attention to the differences between the following two types of sequence

(1) constant sequence (2) arithmetic sequence with negative tolerance

- 2, - 2,... 3, 1, - 1, - 3, ...

students should have a correct understanding of the dialectical relationship between general and special<

case 2: make up a topic of equal ratio series, and study the related properties of equal ratio series

find out typical problems from students' many problems, and study them together with teachers and students, including the examples in the book

(in real life, such as loan to buy a house, population growth and the change of housing area - pay attention to the hot issues around the people, Pay attention to guide students to apply their knowledge to related subjects, life and proction practice, so that students can develop their thinking ability while acquiring and applying knowledge, so that students can use existing knowledge to communicate, and abstract practical problems into mathematical problems and establish mathematical models.)

such as "a foot of the hammer, half of the day, never exhausted", and asked to say its mathematical model, find out its general formula

(both new and old textbooks and textbooks are being compiled, etc.)

5. 1、 Typical problems
typical problems are basic problems, and the basic problems in textbooks and reference books all belong to this category. When doing this kind of questions, we should have such an attitude: making questions is to test the mastery of knowledge points. In the process of making questions, we can't just do them for the sake of making questions. We should think actively and actively, so that we can understand and master knowledge more deeply, and the knowledge we have learned can become our own knowledge, so that we can have independent problem-solving ability
for example, the computation of linear algebra is relatively large, but the possibility of pure computation is relatively small. Generally, there is computation in proof and computation in abstraction. This requires candidates to pay attention to the strict logic of the proof questions, and master the basic use methods of some knowledge points in proving some conclusions. Although the examination of linear algebra can be very flexible, the use methods of these basic knowledge points are relatively fixed, as long as they are familiar with various splicing methods< Second, simulation problems are generally higher than real problems in terms of difficulty. For this kind of problems, it is used to expand the field of exercises, so don't worry too much about whether you do well. Even if you don't do well, you don't need to be too discouraged. If you can do it all, you should go directly to the test instead of the test
in addition, it is suggested that candidates should prepare two notebooks when reviewing. One is to sort out the knowledge points, formulas and theorems they don't understand in the review; the other is the wrong questions book, which can accumulate the wrong questions they encounter in the review. In the early stage of review, we can't see the important role of these two books, but the more we review, we will find the importance of these two books. These two books are the most suitable materials for us to review
finally, at this stage, I hope you can form a serious habit of doing problems. Many students will fail to get points even though they know how to do problems, mostly because they don't solve problems seriously. So at the beginning of the review, train yourself to use the draft paper reasonably, try to write more regular and serious, so as to rece the error rate. You should know that the big questions on the test paper are still better, there are still steps, and there is no point for the small questions
3. The resources of real questions over the years are limited. If you just do the questions, even if you do them three or five times, you can finish them at once. Therefore, when you do the real questions, you must devote yourself to doing them. Take the real questions of each year as examination questions, grasp the time, and control the time for each real question within two and a half hours, After finishing, according to the grading standard given by the examiners of postgraate entrance examination, score their own papers, record and analyze the mistakes in the papers, find out the places that do not conform to the answers given by the examiners, graally improve their own ideas, and graally move closer to the ideas of the examiners. In addition, in addition to doing real questions, you should also learn to summarize the real questions over the years, and list the test points in the real questions over the years into a table, which can help you predict the test points
in the end, I have to mention the spirit of making questions. Most of the examinees think that if they want to learn mathematics well, they can get high marks as long as they do more questions. In fact, it's not the case. It's very unlikely to get a high score by using sea fighting. Many students who got into famous universities with high marks mentioned it several times when they introced the learning methods of mathematics. However, it should be noted that they pay more attention to doing this set of questions over and over again, not simply repeating, but summing up experience and methods in doing the questions. Therefore, we need to strengthen the training of a certain number of problems, slowly improve their problem-solving speed and proficiency, and strengthen the in-depth understanding of knowledge points. Even if we only improve the computing ability, we also need to "gnaw" and "drill".

6. To fill in the project application form, we should pay attention to the problem of "project name": we should accurately and normatively express the content, scope and object of the project research. 1. It is necessary to make a high degree of generalization, express the problems to be studied and the main contents in the most concise language, and properly reveal the relationship between the name of the subject and the central argument of the subject&# 8226; The language must be accurate, clear, specific and scientific. Generally speaking, it should be expressed in declarative sentences, not in the form of questions such as "how to cultivate..." or in the form of slogans and conclusions&# 8226; The expression of subject name should also avoid value judgment. For example: good study habits are the basis of improving middle school students' Chinese learning achievement. Research on Cultivating Middle School Students' good study habits should be reformed. Research on Cultivating Middle School Students' good study habits and improving Chinese learning achievement should be carried out. 2. Specific problems should be in line with the reality of research, Don't make a mountain out of a molehill. Example 1: research reform of students' learning rules: Research on guidance of students' learning methods (narrow the scope of research). Example 2: research reform of giving full play to students' main role: add "in primary school" and "in classroom teaching" (add restrictive attribute). 3 The expression of the topic should conform to the basic requirements. The topic of the topic can include three parts: ① the object of study; ② the problem of study; ③ the method of study. Example 1: the investigation and study of primary school students' extracurricular reading in a county; example 2: the study of guiding students to learn cooperative learning in junior middle school mathematics teaching (research method may not appear); example 3: self-learning The basic requirements for the expression of the research on the formation of ability (the research object may not appear): there should be (1) the research object, (2) the research problem; Unit: write the full name of the unit, so as to avoid the loss of declaration and other materials e to incomplete information; The starting and ending time of the research: preferably two to three years, no project will be approved within one year. Research time is sufficient to avoid the suspicion of quick success and instant benefit&# 8226; County, city and district submit the project before March 20 and September 20 every year. Conclusion: twice a year for provincial and municipal projects: once a year for provincial projects (September); City: the problems that must be specified in the project application twice a year (March and September): 1. There is a subject name that meets the requirements; 2. There are clear research objectives and specific development objectives (for project research, teachers, students and teaching); 3 There are specific research contents (hierarchical decomposition of the subject) divided into several parts, each part has the background of sub project research: most of the primary and secondary ecation research subjects come from the problems and phenomena in the ecation and teaching practice. Research objectives: the objectives of the subject research and the specific problems to be solved. Mainly direct targets. The goal of ecational scientific research is the same as the basic goal of daily ecational work, but the direct and specific goals are not the same. Theoretical hypothesis: according to the theory of ecational science and their own knowledge and experience, the researchers put forward preliminary ideas and predictions for the results of the research. Basic content: decompose the subject hierarchically, make clear the key and difficult points of the specific problems to be solved; explain the key and difficult points of the subject research content; state the research status of similar subjects at home and abroad; elaborate the history and current situation of the subject research at home and abroad, as well as the expected characteristics and breakthroughs. Highlight the value and significance of the research, the theoretical and practical significance of this topic: clear why to study this topic, what is the theoretical and practical significance of the research? The whole research process is generally divided into three stages: preparation, implementation and conclusion; Preparation stage: (i.e. declaration and project approval stage). From the time of project application to the time of project approval, the main contents are as follows: select the project and state the hypothesis; Design the research plan; Collect relevant research data&# 8226; Implementation stage: it is the core of the whole project research. It is necessary to decompose the content and objectives of the project research, and implement the research steps from near to far, from shallow to deep. In each step, we must make the research content, the goal, the time and the research methods concrete to make it operable&# 8226; Conclusion stage: sorting and analyzing the research data; Write the final report; Apply for closing. Problems to be paid attention to when filling in the closing report (1) periodic summary. Each stage (generally a semester is a stage) should have a stage summary, which is indispensable 2) Planned information. Including our project application, project design, project research implementation plan and implementation plan 3) Process data. Including experiment record, such as experiment lesson plan, courseware and CD-ROM; Observation records, essays, social parents' reflection, meeting minutes and photos of research activities, etc 4) Investigation data. Such as survey report, questionnaire, etc 5) Effectiveness data. Such as the change information of the research object, the teacher's paper, the award certificate, the student's work and so on. 2、 What kind of work should we do well in the project research? ① To formulate the implementation plan of the research project; to formulate the annual work plan; to consult the relevant data Carry out necessary investigation, determine experimental objects or establish experimental sites, hold topic opening meeting, carry out special research (combined with observation class), introce research contents into class, establish project archives, write periodical summary, write relevant papers, etc At the end of the project, we should focus on the following work: 1. Write the periodical summary of the implementation of the project, the writing requirements of the annual summary of the project. The content of the annual summary is divided into three parts: ① the implementation of the project (what research activities have been carried out and what research has been carried out); ② The theoretical understanding of the subject research. There should be a research center every year and what research conclusions have been drawn. ③ The existing problems. According to the problems of the research center, a title should be drawn up for the annual summary“ ××××××××××—— Topic 2 × Stage summary ". 2. Carefully write the research report. The basic format of the research report is as follows: background, purpose, content, method, implementation steps, theoretical and practical results, problems and reflections. The key parts are: 1. Theoretical results (main conclusions): according to the main research contents in the report, Write the conclusion of the research (theoretical knowledge). ② Practical results: use examples and data to explain the actual effect of the research (the change and development of teaching, students and teachers), the publication or award of relevant papers, the award of relevant high-quality courses, and the award of students' related activities, etc. 3. Compile the general catalogue of closing materials and the compilation of closing application materials, according to the materials of project initiation, research implementation, research implementation, etc The materials of research achievements are divided into three parts: 1) project application (); 2) project certificate (); 3) project implementation part: 1) project implementation plan; 4) project implementation plan; ② Annual work plan of the project; ③ Annual work summary of the research project (4) special investigation materials (questionnaire, interview, consultation record, investigation report, etc.); ⑤ Project research activities; ⑥ Evaluation materials (school teachers and students and social evaluation reflection) and other research achievements: ① Research Report; ② The main thesis of the subject research (comprehensively expounding the main content of the subject research); ③ Research related papers; ④ Project research typical lesson; ⑤ The achievements of the students in the project research (2-3 selected ones) and so on (in this year's province) are especially emphasized (in the future): ｛ 8226; If there are two or more persons in charge of the project in the application form for project initiation and project closure, they will not be approved&# 8226; If the host is replaced at the end of the project, it will not be approved and the project must be re applied, but the research time can be shortened (it can be indicated in the application form)&# 8226; If the closing declaration uses the old form, it will not be approved&# 8226; If there is no of the project application form in the closing materials, it will not pass (cannot be compared)&# 8226; If the closing materials are messy or not listed separately in the closing report, it shall be regarded as "irresponsible to oneself, and the reviewer shall not be responsible to him"&# 8226; It is recommended that the projects within 2-3 years should not be established or concluded within one year.

7. What I sum up is "slow is fast". Slowing down the speed of solving problems can improve the accuracy. In the exam, sometimes five minutes can write two big questions, but sometimes 20 minutes can not write a problem, because it is difficult. But those two big problems didn't get full marks because of the fast calculation, and then the difficult problem won't get no scores, is it very hurt? I always write the first two big questions slowly, so as to ensure that they are correct. If I can't solve them later, I can get the first score.

8. Develop a good habit of learning mathematics.
query more, think more, practice more, summarize more, and pay attention to application. In the process of learning mathematics, students should translate the knowledge taught by teachers into their own special language, and remember it in their own mind forever. Good habits of learning mathematics include self-study before class, paying attention to class, reviewing in time, working independently, solving problems, etc The main points of middle school mathematics learning are as follows: collection and correspondence, classified discussion, combination of number and form, movement, transformation and transformation; After having the mathematical thought, we should master the specific methods, such as: exchange element, undetermined coefficient, mathematical inction, analysis, synthesis, counter evidence, etc. in the specific methods, the common ones are: observation and experiment, association and analogy, comparison and classification, analysis and synthesis, inction and dection, general and special, finite and infinite, abstract and generalization, etc; When solving mathematical problems, we should also pay attention to the problem-solving thinking strategies. We often need to think about: what angle to choose and what principles to follow. The mathematical thinking strategies often used in senior high school mathematics are: controlling the complex with simplicity, combining numbers and shapes, using advance and retreat mutually, turning students into proficient ones, turning students into proficient ones, turning students into proficient ones, turning students into proficient ones, turning students into proficient ones It is not taught by teachers, but acquired by their own active thinking activities under the guidance of teachers.
learning mathematics must pay attention to "living". It is not good to only read books without doing problems, to only concentrate on doing problems without summing up accumulation.
according to their own learning situation, Some specific measures should be taken; Take notes on mathematics, especially the different aspects of understanding concepts and mathematical laws, and extracurricular knowledge teachers develop in class. Record the most valuable thinking methods or examples in this chapter, as well as the unsolved problems you still have, so as to make up for them in the future; Establish a mathematical error correction book. Record the knowledge or reasoning that is prone to make mistakes in order to prevent recurrence. Strive to do: find, analyze, correct and prevent mistakes. Achieve: to understand the correct things from the opposite side; to understand the correct things from the wrong side; to understand the correct things from the wrong side; Guo Shuo can find out the cause of the mistake so as to suit the remedy to the case; The answers are complete and the reasoning is rigorous; We often sort out the knowledge structure to form a plate structure, and implement "integrated packaging", such as tabulation, so as to make the knowledge structure clear at a glance; We often classify exercises from one example to one, from one to many, and from many to unity; Make several kinds of problems summed up in the same knowledge method.
Review in time, strengthen the understanding and memory of the basic concept knowledge system, carry out appropriate repeated consolidation, eliminate the forgetting after learning.
learn to summarize and classify from multiple angles and levels, such as: ① from the classification of mathematical thinking; ② from the classification of problem-solving methods; ③ from the classification of knowledge application, so as to systematize and organize the learned knowledge Special topic, network.
often after doing some "reflection", think about the basic knowledge used in this problem, what is the mathematical thinking method, why do you want to think so, whether there are other ideas and solutions, the analysis method and solution of this problem, whether they have been used in solving other problems

9. Develop a good habit of learning mathematics
more questions, more thinking, more hands-on, more inction and more application. In the process of learning mathematics, students should translate the knowledge imparted by teachers into their own special language and keep it in their mind forever. A good habit of learning mathematics includes self-study before class, concentration in class, timely review, independent homework, problem solving, systematic summary and extracurricular learning
understand and master the commonly used mathematical ideas and methods in time
&61548; The mathematics thoughts that middle school mathematics learning should focus on are as follows: set and corresponding thought, classified discussion thought, number shape combination thought, movement thought, transformation thought, transformation thought< br /> After having the mathematical thought, we should master the specific methods, such as: exchange element, undetermined coefficient, mathematical inction, analysis, synthesis, counter evidence and so on. In the specific methods, there are: observation and experiment, association and analogy, comparison and classification, analysis and synthesis, inction and dection, general and special, limited and infinite, abstract and generalization< br /> When solving mathematical problems, we should also pay attention to the problem-solving thinking strategy, and often think about: what angle to choose and what principle to follow. The mathematics thinking strategies often used in senior high school mathematics include: controlling complexity by simplicity, combining number with form, using advance and retreat mutually, turning students into proficient ones, turning students into proficient ones, turning students into proficient ones when facing difficulties, returning them in reverse order, dynamic and static transformation, separating and combining, etc<
graally form a "self-centered" learning mode
mathematics is not taught by teachers, but obtained by their own active thinking activities under the guidance of teachers. Learning mathematics must pay attention to "live", only read a book, do not do the problem, only buried in the problem, do not sum up the accumulation is not good
according to their own learning situation, take some specific measures; Take notes of mathematics, especially the different aspects of understanding concepts and mathematical laws, and teachers' extracurricular knowledge in the classroom. Write down the most valuable ideas or examples in this chapter, as well as the unsolved problems you still have, so that you can fill them up in the future< br /> Establish mathematical error correction book. Write down the knowledge or reasoning that is easy to make mistakes in order to avoid making mistakes again. Strive to achieve: find, analyze, correct and prevent mistakes. To achieve: can start from the opposite, in-depth understanding of the right things; Guo Shuo can find out the cause of the mistake so as to suit the remedy to the case; The answers are complete and the reasoning is rigorous< br /> We often sort out the knowledge structure to form a plate structure, and implement "integrated packaging", such as tabulation, so as to make the knowledge structure clear at a glance; We often classify exercises from one example to one, from one to many, and from many to unity; Several kinds of problems are summed up in the same knowledge method< br /> Timely review, strengthen the understanding and memory of the basic concept knowledge system, carry out appropriate repeated consolidation, eliminate forgetting before learning< br /> Learn to summarize and classify from multiple perspectives and levels. For example: ① from the classification of mathematical thinking, ② from the classification of problem-solving methods, ③ from the classification of knowledge application, so that the knowledge learned systematic, organized, thematic, network< br /> Often after doing some "reflection", think about the basic knowledge of this problem, what is the mathematical thinking method, why do you want to think like this, whether there are other ideas and solutions, whether the analysis method and solution of this problem have been used in solving other problems.