Question: what is the greatest common factor of eight and 32?
Answer: The prime factorization of 8 is: 2 x 2 x 2.
The prime factorization of 32 is: 2 x 2 x 2 x 2 x 2.
The prime factors and multiplicities 8 and 32 have in common are: 2 x 2 x 2.
2 x 2 x 2 is the gcf of 8 and 32.
gcf(8,32) = 8.