common factors (GCF) is the biggest factors common to two numbers Commons are factors common to the buvo given numbers. betoon and cous method Berpie Fading the Common Factors and Greatest common Factor (GCF) aby icing the factors of 12 and 18. 12 = 1, 2, 3, 4, 6 ond 12 18 = 1.2.3,6,9, and 18 Common factors 1,2,3,6 GC of 12 and 18 = 6