How do you calculate the Greatest Common Factor?

Expert Answers
hala718 eNotes educator| Certified Educator

If you need to find the GCF for two numbers , follow the following steps:

1. Factor the numbers to its prime factors.

2. multiply the common primes.

 

Example:

Find the GCF for 36 and 54.

1. Factor both numbers.

36 = 2*2*3*3

54= 2*3*3*3

Now we will multiply the common factors (in bold line).

==> GCF = 2 * 3*3 = 18

Then, the greatest common factor is 18.

 

Example (2);

Find the GCF for 48 and 64.

1. Factor both numbers.

==> 48= 2*2*2*2*3

==> 64 = 2*2*2*2*2*2

2. Choose common primes and multiply.

==> GCF = 2*2*2*2= 16

 

atyourservice | Student

You find the biggest common number 2 numbers can be divided by.