# How do you find the greatest common factor of 36, 12?

Nov 5, 2016

The long way would be to factorize both numbers into primes.

#### Explanation:

$36 = 2 \times 2 \times 3 \times 3$
$12 = 2 \times 2 \times 3$
Primes they both have in common:
$2 \times 2 \times 3 = 12$

But you could also have seen that:
$36 = 3 \times 12$
$12 = 1 \times 12$

The long method always works, but seeing may allow you a sortcut.