# What is the GCF of 18 and 20?

The largest possible number which divides the given numbers exactly without any remainder is called the Greatest Common Factor.

## Answer: The GCF of 18 and 20 is 2

## Explanation:

Two methods to find the GCF of 18 and 20 are explained below.

### Methods to find GCF of 18 and 20

We can find the GCF by the following methods

- Prime factorization Method
- Listing the common factors method

### Calculate GCF of 18 and 20 by Prime Factorization

Let us represent 18 and 20 as a product of its prime numbers.

Prime factorization of 18 is 2 × 3 × 3

Prime factorization of 20 is 2 × 2 × 5

The common factor in the prime factorization of 18 and 20 = 2

GCF is the product of the factors that are common to each of the given numbers.

So, GCF of 18 and 20 is 2

### Calculate GCF of 18 and 20 by Listing the Common Factors

The factors of 18 and 20 are shown below.

Clearly, the common factors of 18 and 20 are 1 and 2

The greatest common factor of 18 and 20 is 2

You can find the GCF in any of the above methods but the solution will be the same.