what is a common factor

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

A common factor refers to a number that divides exactly into two or more numbers. In other words, it's a number that can evenly divide two or more given numbers without leaving a remainder. For example, the common factors of 12 and 18 are 1, 2, 3, and 6 because all of them can divide both 12 and 18 without a remainder.

To find the common factors of two numbers, you can follow these steps:

1. List all the factors of the first number.
2. List all the factors of the second number.
3. Identify the numbers that appear in both lists.
4. Those numbers are the common factors.

For example, let's find the common factors of 12 and 18:

Factors of 12: 1, 2, 3, 4, 6, 12
Factors of 18: 1, 2, 3, 6, 9, 18

The common factors are 1, 2, 3, and 6.