First, fill in the name of the algorithm in the brackets. (10)

1.a+b= b+a()

2.(a+b)+c= a +(b+c)()

3.(a+b)×c= a ×c+b×c()

4.(a×b)×c= a ×(b×c)()

5.a×b= b×a()

Fill in the blanks according to the algorithm. (10)

1.85×a= a×□

2.85×(20+4)=85○20○□×4

3.38×99+38=38×(□+□)

4. 185×46- 125×46=□○(□-□)

5.25× 18×4=(□○4)○ 18

Third, the judge. (Tick √ in brackets for correctness, tick ×) for error. 10)

1.4 1× 10 1-4 1=4 1×( 10 1-4 1) ( )

2.70 1× 19=700× 19+ 1 ( )

3.47×38-38× 17=38×(47- 17) ( )

4.305×23=300+5×23 ( )

5.69×23+23=23×(69+ 1) ( )

Fourth, the calculation problem.

1. Write the number directly. (12)

45×4= 30×40= 80×20= 400×20= 200×5= 40×60=

700÷70= 320-50= 53+ 17= 180÷20= 880÷80= 45÷ 15=

2. Use a simple method to calculate. (27 points)

40 1×25 78× 103-3×78 125×(8+ 10)

28+28×59 30 1×2 1-2 1 43×23+57×23

78×99 25×(40+4) 48 1× 10 1-48 1

Fifth, solve the problem. (3 1)

Class 4 (1) and Class 4 (2) participated in the spring tree planting activities, and each of them planted 5 trees on average. There are 42 students in Class Four (1) and 48 students in Class Four (2). How many trees have they planted?

2. A coat 128 yuan and a pair of pants 72 yuan. Aunt Wang is going to buy 15 sets of such clothes. How much money should she bring at least?

3. suguo supermarket imported three kinds of fruits, as shown in the following table:

Types of apples, oranges and pears

Number of cases

Weight per case (kg) 24 24 34

(1) How many kilograms did oranges and apples bring in?

(2) How many kilograms are pears brought in than oranges?

4. Make a parallelogram frame with steel pipe. Its two adjacent sides are 8m and10m respectively. If 50 yuan is needed for each meter of steel pipe, how much does it cost to make this framework?

The unit price of these four books is as follows:

Journey to the West Unit Price: 22 yuan Dream of Red Mansions Unit Price: 24 yuan

Water Margin Unit Price: 28 yuan Romance of the Three Kingdoms Unit Price: 26 yuan.

(1) Buy 15 copies of Journey to the West and Water Margin respectively. Is it enough to bring 800 yuan?

(2) How much does it cost to buy 12 sets of Four Great Classical Novels?

(3) Ask a question and answer it yourself.

6. The master and the apprentice began to process the parts at the same time. The master processes 50 parts per hour and the apprentice processes 36 parts per hour. A few hours later, the master processed 56 more parts than the apprentice.