Alternatively, the gcf of 12 and 56 can be found using the prime factorization of 12 and 56:
The prime factorization of 12 is: 2 x 2 x 3.
The prime factorization of 56 is: 2 x 2 x 2 x 7.
The prime factors and multiplicities 12 and 56 have in common are: 2 x 2.
2 x 2 is the gcf of 12 and 56.
gcf(12,56) = 4.