# What is GCF of 42 and 72?

GCF of two numbers 42 and 72 is the largest possible number which divides both the numbers exactly.

## Answer: GCF of 42 and 72 is 6

Let us see few ways to find the GCF of 42 and 72.

## Explanation

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

## Methods to Find GCF of (42,72)

- Listing the common factors
- Long division

### Method 1: GCF of 42 and 72 by Listing the Common Factors

In this method, we list all the factors of 42 and 72, then identify the common factors.

The highest among the common factors is the GCF of 42 and 72.

The factors of 42 are **1,** **2,** **3,** **6,** 7, 14, 21, 42

The factors of 72 are **1,** **2,** **3,** 4, **6,** 8, 9, 12, 18, 24, 36, 72

Common Factors of 42 and 72: 1, 2, 3, 6.

Greatest common factor= 6

GCF of 42 and 72 is 6

### Method 2:GCF of 42 and 72 by Long Division

- Step 1: Divide 72 by 42 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 remainder as 0

GCF of 42 and 72 always 6 and is invariant with the method we choose to find it.