COMMON MULTIPLES.

When you multiply a given whole number by any other whole number, the result is a multiple of that number.

For example, 5 is the first multiple of 5 (because 5 x 1 = 5),
10 is the second multiple of 5, and so on.
Example 1:
Write down the first 3 multiples of 8.
Solution: 8 x 1 = 8, 8 x 2 = 16, 8 x 3 = 24, so the first 3 multiples of 8 are 8,16,24.

Example 2:
Write down all multiples of 3 greater than 10 but smaller than 20.
Solution: Multiples of 3 are 3, 6,9,12,15,18,21,24,...
The desired ones are 12,15,18.

The common multiples of two numbers are multiples of both numbers.

Example 1:
Find common multiples of 3 and 5.
Solution: Multiples of 3 are 3,6,9,12,15,18,21,24,27,30,33,...
Multiples of 5 are 5,10,15,20,25,30,35,...
Common multiples of 3 and 5 are 15, 30, ...

Example 2