Table of Contents

## Definitions

**Factors** are numbers we multiply together to get another number.

When we find the factors of two or more numbers, and then find some factors are the same (common), they are the common factors.

Factors of two (or more) numbers have in common are called the

of those numbers.common factors

## Example

Example: 20 and 25

• The factors of 20 are: 1, 2, 4, 5, 10 and 20

• The factors of 25 are: 1, 5, and 25

So the common factors of 20 and 25 are: 1 and 5