The biggest common factor number is the GCF number. So the greatest common factor 9 and 14 is 1.
It's one, because if you take the prime factorization of both 9 and 14 only 1 comes out more than once in the factor tree.
The factors of 9 are 1, and 3
The Factors of 14 are 1, 2 and 7
Both 9 and 14 have 1 as a factor. It's the greatest common factor.
