![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
Method 1:
\List the factors of each number.
\Factors of 24: 2, 3, 4, 6, 8, 12, 24.
\Factors of 40: 2, 4, 5, 8, 10, 20, 40.
\Identify the greatest common factor.
\The greatest common factor of 24 and 40 is 8.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step2.JPG\")
Method 2:
\Write the prime factorization of each number.
\24 = 2 × 2 × 2 × 3.
\40 = 2 × 2 × 2 × 5.
\The GCF is the product of the common prime factors in each number.
\GCF = 2 × 2 × 2 = 8.
\The greatest common factor of 24 and 40 is 8.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
The greatest common factor of 24 and 40 is 8.