Question: what is the greatest common factor for 7 and 8?
Answer: The prime factorization of 7 is: 7.
The prime factorization of 8 is: 2 x 2 x 2.
The prime factors and multiplicities 7 and 8 have in common are: 1.
1 is the gcf of 7 and 8.
gcf(7,8) = 1.