1. If A is a multiple of B, then the least common multiple of A and B is B. (x)

2.A and B are two different prime numbers, and the least common multiple of A and B is the product of A and B .. (√).

3. The least common multiple of odd and even numbers is the product of these two numbers. (×)

4. The common multiple of two natural numbers cannot be less than these two numbers. (√)

5. The least common multiple of two numbers must be greater than these two numbers. (×)

3. A rectangular brick is 3 centimetres long and 2 centimetres wide. There is no need to cut a square with this brick. What is the area of this square at least? =6

6*6=36 square decimeter

☆4. There is a pack of biscuits, whether it is distributed to 8 children on average or 10 children, it is 5 pieces for a lifetime. How many cookies are there in this packet? [8, 10]=40

40+5=45 (block)

Page P 17 has the following title ↓

3. Write the greatest common factor of each group in brackets.

5 and 7( 1)

15 and 3(3)

26 and 14(2)

12 and 10(2)

Articles 8 and 20 (4)

4 1 and 6( 1)

5 1 and 17( 17)

25 and 10(5)

4. Cut a rectangular piece of paper with a length of 30 cm and a width of 24 cm into a square with the same size, as large as possible, without redundancy. What is the side length of the cut square? How many squares can you cut like this? (Draw first, then think)

(30,20)=6

30/6=5

24/6=4

4*5=20

If you lengthen it by 6, you can cut 20 pieces.

() means the greatest common factor [] means the least common multiple.