Fill in the blanks

1.9; 27; 27; nine

2.750

3.30; 990

4. Three "four digits" (4290, 4590, 4890)

5.2; three

6. 17(2、3、5、7)

7.39 1( 17、23)

8.2 10=2×3×5×7; 16; 23 10; 2

9.6; 24; 14; 15

10. 1, 12 or 3,4

1 1.b； a

12. 1; abdominal muscle

13. 14; Forty two.

14.59

15.52; 13; 13; 52; 52; 13

16.②⑥; ①②④⑥

17.4,9 or 8,9 or 9, 10

18. 198 or 192

19.8520; 2085

20.0 or 6(9 120, 9 126)

2 1. Abdominal muscles

22.400( 135=5×3×3×3, 1925=5×5×7× 1 1,486=2×3×3×3×3×3)

Two. Multiple choice

23.D

24.A

25.C

26.D

27.A

28.D

3. Find the minimum common multiple and maximum common factor of the following groups.

29.(87, 145)=29; = 144

3 1.(35,56, 105)=7; =22440

Step 4 solve the problem

33.4+ 15=9+ 10

4+ 15+9+ 10=38

34. 144÷(2+3+7)= 12

So these three numbers are 24, 36 and 84 respectively.

35.954,873,62 1

36.260=2×2×5× 13=4×65

37.- 1=59

38.= 12

3×8÷ 12+ 1=3

39.63+9 1+ 129-25=258

258=2×3×43

So this integer is 43.