Greatest Common Factor (GCF)

A greatest common factor (GCF) is a the largest factor that two numbers have in common.

Example: What is the GCF of 12 and 18?

• • Factors of 12: 2, 3, 4, 6

  • Factors of 18: 2, 3, 6, 9

    • Common factors: 2, 3, 6

      • GCF: 6