What is the gcf of 9 and 12?

The greatest common factor (GCF) of 9 and 12 is 3. This means that 3 is the largest positive integer that divides both 9 and 12 exactly without leaving a remainder. The factors of 9 are 1, 3, and 9, whereas the factors of 12 are 1, 2, 3, 4, 6, and 12. The GCF is always the product of the common factors of two numbers that are largest in value. Since 3 is a common factor of 9 and 12 that is largest in value, it is the GCF of 9 and 12.