Please give an example to illustrate the power of decimal multip
Publish: 2021-05-14 18:52:54
1. The operation order of decimal multiplication and division is the same as that of integer multiplication and division
decimal multiplication
the calculation method is: first, according to the calculation method of integer multiplication, after the proct is obtained, we can see how many decimal places there are in the two factors, and then we can count out several decimal places from right to left in the multiplied proct
the calculation method of decimal division is: first, according to the property of constant quotient, make the divisor into an integer, and then proceed according to the calculation method of integer division, but pay attention to that the decimal point of quotient should be aligned with the decimal point of the divisor.
decimal multiplication
the calculation method is: first, according to the calculation method of integer multiplication, after the proct is obtained, we can see how many decimal places there are in the two factors, and then we can count out several decimal places from right to left in the multiplied proct
the calculation method of decimal division is: first, according to the property of constant quotient, make the divisor into an integer, and then proceed according to the calculation method of integer division, but pay attention to that the decimal point of quotient should be aligned with the decimal point of the divisor.
2. Let's put it this way:
you can divide an integer, just like a decimal. Finally, you can put the decimal point in the right position. Especially, when the first digit is less than the divisor,
it is equivalent to moving the decimal point several places to the right to make the decimal become an integer (imagine that the decimal point is after the last digit), and then moving the corresponding digits to the left after the division, For example:
0.112 ÷ 2
0.112 to become an integer, the decimal point needs to be moved 3 digits to the right
now calculate 112 ÷ 2 = 56, now imagine 56 is 56. We have omitted the decimal point
and then we move the 3 digits that we just moved to the right back to the left, which is not enough to make up for 0 and become 0.056
no matter how the decimal point is divided by integers before, we can put the decimal point back to the corresponding position
you can divide an integer, just like a decimal. Finally, you can put the decimal point in the right position. Especially, when the first digit is less than the divisor,
it is equivalent to moving the decimal point several places to the right to make the decimal become an integer (imagine that the decimal point is after the last digit), and then moving the corresponding digits to the left after the division, For example:
0.112 ÷ 2
0.112 to become an integer, the decimal point needs to be moved 3 digits to the right
now calculate 112 ÷ 2 = 56, now imagine 56 is 56. We have omitted the decimal point
and then we move the 3 digits that we just moved to the right back to the left, which is not enough to make up for 0 and become 0.056
no matter how the decimal point is divided by integers before, we can put the decimal point back to the corresponding position
3. (1) Decimal multiplied by integer: the same meaning as integer multiplication, which is a simple operation to find the sum of several identical addends. For example: 2.5 × 6 is the sum of 6 2.5 or 6 times of 2.5 2) In fact, the meaning of multiplying a number by a decimal is similar to that of multiplying a decimal by a fraction, such as 0.1 × 0.1 is 0.1 of 0.1. What is 0.1? What is 1 / 10 of 0.1? Decimal multiplied by decimal and decimal multiplied by integer are a little similar, which depends on your own understanding. In fact, they are tens, percentages and thousandths of a number
4. The story of decimal point: Zhu Bajie sells vegetables
it is said that after the monkey king returned to Huaguo Mountain from the west, he often turned into a mortal to help
on this day, I made an appointment with Bajie to help people everywhere. Bajie and Wukong come to the farmer's market and see a farmer's uncle selling radishes and tomatoes. It's full of people around. It turned out that there was a big sale of radish and tomato
"radish costs 0.5 yuan per kilogram, tomato costs 1.2 yuan per kilogram." The farmer's uncle yelled
"let's help the farmer uncle to sell vegetables. You can see how fortunate he is." Zhu Bajie suggested. The monkey king agreed, and they changed into two pupils with red scarves on their chests, one fat and the other thin. Soon obtained the farmer uncle's approval, may take up a post formally
"I'll buy 2 yuan radish." An old woman said to Bajie“ OK, here you are Bajie weighed the dishes casually
"how many kilos are there?" Asked the old woman
"Er, this... 2 ÷ How many kilos is 0.5? " Bajie is in trouble
"I'll do it!" Wukong helps Bajie weigh the radish again and hands it to grandma, "2 ÷ 5 = 4, which is 4000 grams. "
"I want to buy 3 yuan tomato." An aunt said“ This is your dish. " Bajie quickly weighed out the weight with the help of Wukong
"is your scale accurate? I'll buy it for three yuan. How many kilos is it? " Aunt saw two primary school students, a little uneasy to ask
Wukong said: "3 ÷ 1.2 = 2.5, you bought 2.5kg. " On hearing this, my aunt left with satisfaction
in his leisure time, Bajie asked Wukong, "monkey, how can you calculate so fast?"
"I move the decimal point. It's much easier to move the decimal point and turn these two problems into division where divisor is an integer. " Goku continued, "put two ÷ 0.5 to 20 ÷ 5 Three more ÷ 1.2, first move the decimal point of divisor one place to the right, and 1.2 becomes 12; Then move the decimal point of the divisor one place to the right and the decimal point of 3 one place to the right to become 30, 30 ÷ 12＝2.5 But note that the divisor and the decimal point of the divisor must move the same number of digits to the right. "
"if it wasn't for your help, I would be ashamed. Thank you, monkey! "
they soon helped the farmer sell out the radish and tomato, and the farmer said thank you! Bajie is the happiest
there are also some small stories, such as:
moving the decimal point (Mastering the law of decimal size change caused by decimal point movement)
understanding that if the decimal point moves one place to the left, the decimal will be reced to one tenth of the original; Move the decimal point two places to the left, and the decimal will be reced to one percent of the original... And so on<
Street Square (the relationship between the decimal places of the proct and the decimal places of the multiplier)
the relationship between the decimal places of the proct and the decimal places of the multiplication: the sum of the decimal places of each factor in the decimal multiplication is the decimal places of the proct in this problem
packing box (decimal multiplication 2)
decimal multiplication calculation method, that is, decimal multiplication is converted into integer multiplication for calculation. According to the multiplier expansion multiple, rece the proct by the same multiple, and further realize that two multipliers have several decimal places in total, and the proct has several decimal places<
the slowest crawling mammal (decimal multiplication 3)
further understand the calculation method of decimal multiplication, that is, there are several decimal places in the proct of two factors; When one of the factors is an integer ten, if there is a decimal place in the proct, a zero will be drawn at the end...
hand in hand (mixed operation of decimal)
if there is a decimal place in the proct, the operation order of mixed operation of decimal four is the same as that of mixed operation of integer four. The law of integer operation is still applicable to decimal operation. For example, the combination law of multiplication, the exchange law and the distribution law. Wait
there are many examples of small tree multiplication and division in our life, such as the electricity consumption of your home, 50.8 degrees, 63.2 tons of water consumption, buying vegetables in the vegetable market,
2.5 yuan of cabbage, buying a catty and a half, and so on.
it is said that after the monkey king returned to Huaguo Mountain from the west, he often turned into a mortal to help
on this day, I made an appointment with Bajie to help people everywhere. Bajie and Wukong come to the farmer's market and see a farmer's uncle selling radishes and tomatoes. It's full of people around. It turned out that there was a big sale of radish and tomato
"radish costs 0.5 yuan per kilogram, tomato costs 1.2 yuan per kilogram." The farmer's uncle yelled
"let's help the farmer uncle to sell vegetables. You can see how fortunate he is." Zhu Bajie suggested. The monkey king agreed, and they changed into two pupils with red scarves on their chests, one fat and the other thin. Soon obtained the farmer uncle's approval, may take up a post formally
"I'll buy 2 yuan radish." An old woman said to Bajie“ OK, here you are Bajie weighed the dishes casually
"how many kilos are there?" Asked the old woman
"Er, this... 2 ÷ How many kilos is 0.5? " Bajie is in trouble
"I'll do it!" Wukong helps Bajie weigh the radish again and hands it to grandma, "2 ÷ 5 = 4, which is 4000 grams. "
"I want to buy 3 yuan tomato." An aunt said“ This is your dish. " Bajie quickly weighed out the weight with the help of Wukong
"is your scale accurate? I'll buy it for three yuan. How many kilos is it? " Aunt saw two primary school students, a little uneasy to ask
Wukong said: "3 ÷ 1.2 = 2.5, you bought 2.5kg. " On hearing this, my aunt left with satisfaction
in his leisure time, Bajie asked Wukong, "monkey, how can you calculate so fast?"
"I move the decimal point. It's much easier to move the decimal point and turn these two problems into division where divisor is an integer. " Goku continued, "put two ÷ 0.5 to 20 ÷ 5 Three more ÷ 1.2, first move the decimal point of divisor one place to the right, and 1.2 becomes 12; Then move the decimal point of the divisor one place to the right and the decimal point of 3 one place to the right to become 30, 30 ÷ 12＝2.5 But note that the divisor and the decimal point of the divisor must move the same number of digits to the right. "
"if it wasn't for your help, I would be ashamed. Thank you, monkey! "
they soon helped the farmer sell out the radish and tomato, and the farmer said thank you! Bajie is the happiest
there are also some small stories, such as:
moving the decimal point (Mastering the law of decimal size change caused by decimal point movement)
understanding that if the decimal point moves one place to the left, the decimal will be reced to one tenth of the original; Move the decimal point two places to the left, and the decimal will be reced to one percent of the original... And so on<
Street Square (the relationship between the decimal places of the proct and the decimal places of the multiplier)
the relationship between the decimal places of the proct and the decimal places of the multiplication: the sum of the decimal places of each factor in the decimal multiplication is the decimal places of the proct in this problem
packing box (decimal multiplication 2)
decimal multiplication calculation method, that is, decimal multiplication is converted into integer multiplication for calculation. According to the multiplier expansion multiple, rece the proct by the same multiple, and further realize that two multipliers have several decimal places in total, and the proct has several decimal places<
the slowest crawling mammal (decimal multiplication 3)
further understand the calculation method of decimal multiplication, that is, there are several decimal places in the proct of two factors; When one of the factors is an integer ten, if there is a decimal place in the proct, a zero will be drawn at the end...
hand in hand (mixed operation of decimal)
if there is a decimal place in the proct, the operation order of mixed operation of decimal four is the same as that of mixed operation of integer four. The law of integer operation is still applicable to decimal operation. For example, the combination law of multiplication, the exchange law and the distribution law. Wait
there are many examples of small tree multiplication and division in our life, such as the electricity consumption of your home, 50.8 degrees, 63.2 tons of water consumption, buying vegetables in the vegetable market,
2.5 yuan of cabbage, buying a catty and a half, and so on.
5. Multiplication and division of decimals and decimals
the calculation method of multiplication and division of decimals is as follows
1. Multiplication algorithm of decimal: first, calculate the proct according to the algorithm of integer multiplication, and then look at the number of decimal places in the factor, count the number of decimal places from the right side of the proct and the decimal point on the point; If the number of digits is not enough, make up with 0
2. Decimal division: first move the decimal point of the divisor to make it an integer, and then move the decimal point of the divisor several places to the right (fill in 0 if the number of digits is not enough), and then calculate according to the division rule that the divisor is an integer
the specific method of decimal multiplication
the calculation method of decimal multiplication is: one calculation, two numbers and three strokes
one calculation: first calculate by integer multiplication
binary: count the number of decimal places of the factor, then count the number of decimal places from the right side of the proct, and point the decimal point. If the decimal part of the proct is not enough, zero should be added in front of it< Three strokes: if there is a zero at the end of the decimal, it should be omitted< According to the above method, the example is as follows:
4.37 × 3.8
multiply 437 by integer division first × 38, and then count the proct from the right to three places, and point the decimal point. Note that the vertical alignment method of decimal multiplication column is different from that of decimal addition and subtraction column. Instead of aligning the decimal point, the vertical alignment method of integer multiplication column is used, such as 4.37 × When the column is vertical, 3.8 of the second factor should be aligned with 37 of the first factor
specific method of decimal division:
calculation method of decimal division: move two points to three points, and pay attention to divide the integer part first
one shift: move the decimal point of the divisor back to an integer. According to the property of constant quotient, the decimal point of the divisor is also moved back several places. If the divisor is already an integer, this step will be skipped
divide by two: divide the integer part of the divisor by the divisor first, if the integer part is not enough, divide by 0, and then divide by 0
three points: decimal point, the decimal point of quotient is aligned with the decimal point after the divisor is moved
for example: 16.8 ÷ 28
if the divisor is 28, you can skip the first step directly. The integer part of the divisor is 16. If 16 divided by 28 is not enough to divide, you should quotient 0 and then divide it in turn.
the calculation method of multiplication and division of decimals is as follows
1. Multiplication algorithm of decimal: first, calculate the proct according to the algorithm of integer multiplication, and then look at the number of decimal places in the factor, count the number of decimal places from the right side of the proct and the decimal point on the point; If the number of digits is not enough, make up with 0
2. Decimal division: first move the decimal point of the divisor to make it an integer, and then move the decimal point of the divisor several places to the right (fill in 0 if the number of digits is not enough), and then calculate according to the division rule that the divisor is an integer
the specific method of decimal multiplication
the calculation method of decimal multiplication is: one calculation, two numbers and three strokes
one calculation: first calculate by integer multiplication
binary: count the number of decimal places of the factor, then count the number of decimal places from the right side of the proct, and point the decimal point. If the decimal part of the proct is not enough, zero should be added in front of it< Three strokes: if there is a zero at the end of the decimal, it should be omitted< According to the above method, the example is as follows:
4.37 × 3.8
multiply 437 by integer division first × 38, and then count the proct from the right to three places, and point the decimal point. Note that the vertical alignment method of decimal multiplication column is different from that of decimal addition and subtraction column. Instead of aligning the decimal point, the vertical alignment method of integer multiplication column is used, such as 4.37 × When the column is vertical, 3.8 of the second factor should be aligned with 37 of the first factor
specific method of decimal division:
calculation method of decimal division: move two points to three points, and pay attention to divide the integer part first
one shift: move the decimal point of the divisor back to an integer. According to the property of constant quotient, the decimal point of the divisor is also moved back several places. If the divisor is already an integer, this step will be skipped
divide by two: divide the integer part of the divisor by the divisor first, if the integer part is not enough, divide by 0, and then divide by 0
three points: decimal point, the decimal point of quotient is aligned with the decimal point after the divisor is moved
for example: 16.8 ÷ 28
if the divisor is 28, you can skip the first step directly. The integer part of the divisor is 16. If 16 divided by 28 is not enough to divide, you should quotient 0 and then divide it in turn.
6. Decimal multiplication: multiplication of numbers, the same as integer multiplication. A few places after the decimal point of the multiplication factor are in the proct. Count from the back to the front and add the decimal point. If you don't count, fill it with zero. The number of digits after the decimal point is the sum of the number of digits after the decimal point of several factors
decimal division: when there are several decimal places in the divisor, the decimal is expanded by an integral multiple of 10 until the decimal becomes an integer. At the same time, the divisor is expanded by the same multiple as the divisor. Finally, according to the integer division algorithm to calculate the number. If the divisor is expanded with a decimal point, the decimal point of the divisor will be moved to the same position as the divisor.
decimal division: when there are several decimal places in the divisor, the decimal is expanded by an integral multiple of 10 until the decimal becomes an integer. At the same time, the divisor is expanded by the same multiple as the divisor. Finally, according to the integer division algorithm to calculate the number. If the divisor is expanded with a decimal point, the decimal point of the divisor will be moved to the same position as the divisor.
7. Unknown_Error
8. Unknown_Error
9. zero point seven × 8=5.6
0.6 × 0.9=0.54
0.5 × 0.8=0.4
1.2 × 0.4=0.48
1.5 × 0.6=0.9
0.25 × 4=1
0.4 × 0.9=0.36
0.12 × 100=12
7.9 × 100=790
0.42 ÷ 100=0.0042
3.65 ÷ 1000=0.00365
4.2 ÷ 0.7=6
7.2 ÷ 0.6=12
9.6 ÷ 0.6=16
0.63 ÷ 0.9=0.7
11 ÷ 0.1=110
1.45+15 × 6= 1352.250 ÷ five × 8=4003.6 × five ÷ two × 4=604.30 × 3+8=985.400 ÷ 4+20 × 5= 2006.10+12 ÷ 3+20=347.(80 ÷ 20+80) ÷ 4=218.70+(100-10 × 5)=1209.360 ÷ 40= 910.40 × 20= 80011.80-25= 5512.70+45=11513.90 × 2= 18014.16 × 6= 9615.300 × 6= 180016.540 ÷ 9=6017.30 × 20= 60018.400 ÷ 4= 10019.350-80= 27020.160+70=23021.18-64 ÷ 8= 1022.42 ÷ 6+20=2723.40-5 × 7= 524.80+60 ÷ 3=10025.41+18 ÷ 2= 5026.75-11 × 5= 2027.42+7-29= 2028.5600 ÷ 80=7029.25 × 16= 40030.120 × 25= 300031.36 × 11= 39632.1025 ÷ 25=4133.336+70= 40634.25 × nine × 4= 90035.200-33 × 3= 10136.3020-1010=201037.12 × 50= 60038.25 × 8= 20039.23 × 11= 25340.125 ÷ 25=541.4200-2200=200042.220+80= 30043.20 × eight × 5= 80044.600-3 × 200=045.20+20 ÷ 2= 3046.35-25 ÷ 5= 3047.36+8-40= 448.2800 ÷ 40=7049.98 ÷ 14 = 750.96 ÷ 24 = 451.56 ÷ 14 =452.65 ÷ 13 = 553.75 ÷ 15 = 554.120 ÷ 24 =555.200 ÷ 25 = 856.800 ÷ 16 = 5057.840 ÷ 21 =4058.560 ÷ 14 = 4059.390 ÷ 13 = 3060.600 ÷ 15 =4061.72 ÷ 24 = 362.85 ÷ 17 = 563.90 ÷ 15 =664.96 ÷ 16 = 665.78 ÷ 26 = 466.51 ÷ 17 =367.80 ÷ 40 = 268.100 ÷ 20 = 569.100 ÷ 4 =2570.240 ÷ 40 = 671.920 ÷ 4 = 23072.300 ÷ 60=573.64 ÷ 2 = 3274.64 ÷ 4 = 1675.50 ÷ 5 =1076.60 ÷ 8 = 7.577.96 ÷ 4 = 2478.90 ÷ 6 =1579.400+80 = 48080.400-80 = 32081.40 × 80 =320082.400 ÷ 80 = 583.48 ÷ 16 = 384.96 ÷ 24 =485.160 × 5= 80086.4 × 250= 100087.0 × 518= 088.10 × 76= 76089.36 × 10=36090.15 × 6= 9091.24 × 3= 7292.5 × 18= 9093.26 × 4= 7494.7 × 15=10595.32 × 30= 96096.40 × 15= 60097.60 × 12= 72098.23 × 30= 69099.30 × 50=1500100.5 × 700 = 3500
hope to help you
please accept the answer and support me.
0.6 × 0.9=0.54
0.5 × 0.8=0.4
1.2 × 0.4=0.48
1.5 × 0.6=0.9
0.25 × 4=1
0.4 × 0.9=0.36
0.12 × 100=12
7.9 × 100=790
0.42 ÷ 100=0.0042
3.65 ÷ 1000=0.00365
4.2 ÷ 0.7=6
7.2 ÷ 0.6=12
9.6 ÷ 0.6=16
0.63 ÷ 0.9=0.7
11 ÷ 0.1=110
1.45+15 × 6= 1352.250 ÷ five × 8=4003.6 × five ÷ two × 4=604.30 × 3+8=985.400 ÷ 4+20 × 5= 2006.10+12 ÷ 3+20=347.(80 ÷ 20+80) ÷ 4=218.70+(100-10 × 5)=1209.360 ÷ 40= 910.40 × 20= 80011.80-25= 5512.70+45=11513.90 × 2= 18014.16 × 6= 9615.300 × 6= 180016.540 ÷ 9=6017.30 × 20= 60018.400 ÷ 4= 10019.350-80= 27020.160+70=23021.18-64 ÷ 8= 1022.42 ÷ 6+20=2723.40-5 × 7= 524.80+60 ÷ 3=10025.41+18 ÷ 2= 5026.75-11 × 5= 2027.42+7-29= 2028.5600 ÷ 80=7029.25 × 16= 40030.120 × 25= 300031.36 × 11= 39632.1025 ÷ 25=4133.336+70= 40634.25 × nine × 4= 90035.200-33 × 3= 10136.3020-1010=201037.12 × 50= 60038.25 × 8= 20039.23 × 11= 25340.125 ÷ 25=541.4200-2200=200042.220+80= 30043.20 × eight × 5= 80044.600-3 × 200=045.20+20 ÷ 2= 3046.35-25 ÷ 5= 3047.36+8-40= 448.2800 ÷ 40=7049.98 ÷ 14 = 750.96 ÷ 24 = 451.56 ÷ 14 =452.65 ÷ 13 = 553.75 ÷ 15 = 554.120 ÷ 24 =555.200 ÷ 25 = 856.800 ÷ 16 = 5057.840 ÷ 21 =4058.560 ÷ 14 = 4059.390 ÷ 13 = 3060.600 ÷ 15 =4061.72 ÷ 24 = 362.85 ÷ 17 = 563.90 ÷ 15 =664.96 ÷ 16 = 665.78 ÷ 26 = 466.51 ÷ 17 =367.80 ÷ 40 = 268.100 ÷ 20 = 569.100 ÷ 4 =2570.240 ÷ 40 = 671.920 ÷ 4 = 23072.300 ÷ 60=573.64 ÷ 2 = 3274.64 ÷ 4 = 1675.50 ÷ 5 =1076.60 ÷ 8 = 7.577.96 ÷ 4 = 2478.90 ÷ 6 =1579.400+80 = 48080.400-80 = 32081.40 × 80 =320082.400 ÷ 80 = 583.48 ÷ 16 = 384.96 ÷ 24 =485.160 × 5= 80086.4 × 250= 100087.0 × 518= 088.10 × 76= 76089.36 × 10=36090.15 × 6= 9091.24 × 3= 7292.5 × 18= 9093.26 × 4= 7494.7 × 15=10595.32 × 30= 96096.40 × 15= 60097.60 × 12= 72098.23 × 30= 69099.30 × 50=1500100.5 × 700 = 3500
hope to help you
please accept the answer and support me.
10. Unknown_Error
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