1 commutates two (), and the position of () remains the same, which is called multiplicative commutative law.

2, a school uniform, coat 59 yuan, pants 4 1 yuan, buy 2 sets, a * * * needs () yuan.

3、a×6+6× 15= ( )×().

4. Multiplication and division can be expressed as () in letters.

5. When calculating (23× 125)×8, you can calculate () first for simplicity, and this calculation is based on ().

6. To calculate 376+592+24 in a simple way, you must first calculate (), which is based on the law of ().

7, according to the algorithm, in □

( 1)a+(30+8)=(□+□)+8

(2)45×□=32×□

8. fill in ">,

(65+ 13)×4○65×4+ 13×4 720÷36÷2○720÷(36÷2)

Second, the judgment question.

1、 134-75+25= 134-(75+25)。 ( )

2. Multiply the first two numbers, or multiply the last two numbers first, and the product remains unchanged. This is the law of association. ( )

3、 180÷5÷4= 180÷(5×4)。 ( )

4、 125×4×25×8=( 125×8)+(4×25)。 ( )

5.52+83+48=83+(52+48) Only additive commutative law is used in this calculation. ( )

Third, multiple choice questions.

1, 56+72+28=56+(72+28) Use ().

A, additive commutative law B, additive associative law C, additive commutative law and associative law

2. The laws of multiplication and distribution are used in the following formula ().

a . 42×( 18+ 12)= 424×30 b . a×b+a×C = a×(b+C)C . 4×a×5 = a×(4×5)

3、 10 1× 125= ( )

a、 100× 125+ 1 B、 125× 100+ 125 C、 125× 100× 1

4, 49× 25× 4 = 49× (25× 4) This is based on ().

A. Multiplicative commutative law B. Multiplicative distributive law C. Multiplicative associative law

The simple algorithm of 5.986-297 is ().

a . 986-300-3b . 986-300+3c . 986-200-97

Fourth, the calculation problem.

1, oral calculation.

480- 10 1 = answer 598+99 = answer 2 10 ÷ 35 = answer 198÷9= answer 2 10×6= answer/kloc.

2. Vertical calculation.

450×32= answer 604× 19= answer 26×300= answer 670÷3 1= answer 365÷29= answer 207÷30= answer.

3. Simple calculation.

125×48= answer 989- 186- 14 = answer 355+260+ 140+245= answer 98× 10 1=

Fifth, solve the problem.

1, students go to the military region to perform, grade four 1 13, grade five 272, grade six 87. How many people will go in three grades?

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2. A fourth-grade student of a primary school organized a visit to the Science and Technology Museum. There are 204 boys and 96 girls/kloc-0. If every 40 people take a car, how many cars does a car need?

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3. Uncle Li keeps 142 chickens, and the number of ducks is half that of chickens. How many chickens and ducks are there in Uncle Li's house?

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4. The school should make 4800 colorful flags and give this task to 25 classes. There are 4 groups in each class. How many colorful flags should each group make on average?

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5. Dad took Mingming skiing, and the cable car took 10 minutes to climb the mountain, 200 meters per minute. It took 30 minutes to ski downhill, 70 meters per minute. How many meters is skiing more than taking a cable car?

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6. A factory originally planned to produce 4,800 farm tools a year, but actually completed the task in 10 month. How much more farm tools are actually produced each month than originally planned?

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7. There are 80 bags of rice and 80 bags of flour in the school canteen, with 75 kilograms of rice and 25 kilograms of flour. How many kilograms of rice and flour are there? (Please answer in two ways)

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