# What is GCF of 28 and 40?

GCF of two numbers 28 and 40 is the largest possible number which divides both the numbers exactly.

## Answer: GCF of 28 and 40 is 1

Let us see how to find the GCF of 28 and 40

## Explanation:

The greatest common factor of two numbers is the largest possible number which divides both the numbers exactly without any remainder. It is also called the highest common factor or the greatest common divisor.

The commonly used methods to find GCF are listed below.

- Listing the common factors
- Long division

## Methods To Find GCF of 28 and 40

### Method 1:** **GCF of 28 and 40 by Listing the Common Factors

The process is that we list all the factors of 28 and 40, then identify the common factors. The highest among the common factors is the GCF of 28 and 40.

Factors of 28 are 1, 2, 4, 7, 14, 28.

Factors of 40 are 1, 2, 4, 8, 10, 20, 40.

Common Factors of 28 and 40: 1, 2, 4.

The greatest common factor of 28 and 40 = 4

GCF of 28 and 40 is 4

### Method 2: GCF of 28 and 40 by Long Division

Step 1: Divide 40 by 28 and check the remainder.

Step 2: Make the remainder of the above step as the divisor and the divisor of the above step as the dividend and perform the long division again.

Step 3: Continue till you get the remainder as 0

GCF of 28 and 40 is the same as 4 as it is invariant with the method we choose for.