![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
Method 1:
\List the factors of each number.
\Factors of 12: 2, 3, 4, 6, 12.
\Factors of 18: 2, 3, 6, 9, 18.
\Identify the greatest common factor.
\The greatest common factor of 12 and 18 is 6.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step2.JPG\")
Method 2:
\Write the prime factorization of each number.
\12 = 2 × 2 × 3.
\18 = 2 × 3 × 3.
\The GCF is the product of the common prime factors in each number.
\GCF = 2 × 3 = 6.
\The greatest common factor of 12 and 18 is 6.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
The greatest common factor of 12 and 18 is 6.