![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step1.JPG\")
Method 1:
\List the factors of each number.
\Factors of 16: 2, 4, 8, 16
\Factors of 32: 2, 4, 8, 16, 32
\Factors of 40: 2, 4, 5, 8, 10, 20, 40
\Identify the greatest common factor.
\The greatest common factor of 16, 32 and 40 is 8.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/step2.JPG\")
Method 2:
\Write the prime factorization of each number.
\16 = 2 × 2 × 2 × 2.
\32 = 2 × 2 × 2 × 2 × 2.
\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 16, 32, and 40 is 8.![\"\"](\"http://www.mathskey.com/userfiles/image/steps_images/solution.JPG\")
The greatest common factor of 16, 32, and 40 is 8.
\