# How to Find the Greatest Common Factor

## Finding the Greatest Common Factor

The greatest common factor of two or more numbers can be found.

Imagine we wanted to find the greatest common factor of **12** and **18**.

## How to Find the Greatest Common Factor

Finding the greatest common factor is easy.

### Question

What is the greatest common factor of the numbers 12 and 18?

### Step-by-Step:

# 1

# 2

List the factors of **18**.

Factors of 18 = 1, 2, 3, 6, 9, 18

# 3

The largest factor that appears in both lists is the greatest common factor.

Factors of 12 = 1, 2, 3, 4, **6** , 12

Factors of 18 = 1, 3, **6** , 9, 18

### Answer:

**6** is the greatest common factor of 12 and 18.