List the factors of each number
Identify the factors they have in common
Choose the greatest factor that appears in every list
If needed, use prime factorization
Find the common prime factors
Multiply the common prime factors
The result is the GCF
List the factors of each number
Identify the factors they have in common
Choose the greatest factor that appears in every list
If needed, use prime factorization
Find the common prime factors
Multiply the common prime factors
The result is the GCF