2. The fifth battery is about 5 () long.

The length of the rectangle is 8 cm, which is 3 cm longer than the width. The circumference of this rectangle is () cm.

4. The sum of the minuend, the minuend and the difference is equal to 400, and the minuend is ().

5. The quotient and remainder of a number divided by 7 are the same, and this number is ().

6. In the division formula where the remainder is () -8 = 3 ... (), the remainder is () and the dividend is (); The minimum remainder is () and the dividend is ().

There are 30 days in July and April. If April has five Saturdays and Sundays, then April 1 is the week ().

8. Fill in 1, 3, 5 and 7 in () respectively. Fill in () () ×) when making products; To minimize the product, you should fill in () () × ().

9. If you have five cats and eat five fish at the same time, it will take five minutes to finish. It takes () minutes for 100 cats to eat 100 fish at the same speed.

10, the number of books in group A, group B and group C is different. Group B has 40 more books than Group A, Group C has 50 fewer books than Group A, and the number of books in Group B is twice that of Group C. Group A has books (), Group B has books () and Group C has books ().

1 1. When the side length of a square increases by 2 cm, the circumference increases by () cm.

12, a rectangle is10cm long and 8cm wide, and a square is cut out from it. The circumference of this square is () cm.

13, divide an apple into four parts, each part is its () and three parts are its ().

14、 1 9 8 ( )6( ) ( )( )( )

- ( )( ) + 2 ( )6 - ( )( )

- - -

( )( ) 8 0 3 ( )

15, Xiaoming wants to help his mother on Sunday. The following is the time needed for each other:

Washing clothes with washing machine (20 minutes) sweeping the floor (5 minutes) moving furniture (10 minutes) drying clothes (5 minutes)

It will take him at least () minutes to finish all these things.

16. The apples in the first basket weigh 40 kilograms. If you take out 3 kilograms from the first basket and put it in the second basket, the first basket is 2 kilograms more than the second basket. How many Jin does the original B basket of apples weigh?

17. There are 50 colored pens scattered on the desktop, with an average of 8 pens in a box. How many boxes do you need at least?

18 and 3 1 class, there are 37 people who have completed Chinese homework, 42 people who have completed math homework, and 3 1 person who have completed two kinds of homework, each of whom has completed at least one kind of homework. How many students are there in Class Three One?

19, a number multiplied by 4, Xiao Mahu misreads the multiplication sign as a plus sign, and the result is 254. Please help Xiao careless to calculate the correct product.

20. There are white, red and black balls. White ball red ball together * * 15, red ball black ball together * * 18, white ball black ball together ***9, how many are the three kinds of balls?