9 and 12 8 and113 and 26 27 and 18 20 and 24 16 and 4.

3 1 13 9 4 4

2. Find the least common multiple of each group number.

8 and 9 7 and 6 10 and 6

72 42 30

3. There is a bag of candy, whether it is distributed to 8 people or 10 people, it has just been eaten.

(1) How many sweets are there in this package? 40

(2) If 8 people or 10 people have 2 sweets left, how many sweets are there in this package? Forty two.

4.( 1) The maximum factor of a number is 36. This number is (36), and its factor is (12369121836.

(2) The minimum multiple of a number is 16, and this number is (16). Write its three multiples: (16 32 48).

(3) If the integer A is divided by the integer B, the quotient is 8, and there is no remainder, then the greatest common factor of A and B is (8 or B), and the smallest common multiple is (A).

(4) Write down the second digits whose common factor is only 1: (3) and (5). The least common multiple of these two numbers is (15).

5. Fill in their least common multiple in the box behind each group number and their greatest common factor in ().

9 and 7 63 (1) 7 and 35 35 (7) 16 and 24 48 (8)

14 and 2 1 42 (7) 20 and 30 60 (10) 15 and 60 60 (15).

6. Write the greatest common factor of numerator and denominator in the following fractions.

6 15 9 34 18

— ( 3 ) — ( 5 ) — ( 9 ) — ( 17 ) — ( 18 )

9 20 36 5 1 90

7. Write the least common multiple of the two denominators in each group of fractions.

5 7 3 2 4 7 8 5 1 3 2 3

And-and-and-and-

6 8 7 9 9 18 9 6 3 7 5 10

24 63 18 18 2 1 10

8. Cut a rectangular piece of paper with a length of 18cm and a width of 12cm into small squares as long as the whole centimeter. How many pieces can I cut at most? At least?

n*a^2= 18* 12=2*2*2*3*3*3

When the side length is 2,54.

When the side length is 3, there are 24.

When the side length is 6, 6.