GCD by Listing - Arithmetic Step by Step

Find the greatest common divisor of 24 and 36 by listing all factors of each number, identifying the shared ones, and picking the largest. GCD(24, 36) = 12.

Example

gcd-24-36.math

GCD(24, 36)

step: factors of 24: 1, 2, 3, 4, 6, 8, 12, 24
step: factors of 36: 1, 2, 3, 4, 6, 9, 12, 18, 36
step: common factors: 1, 2, 3, 4, 6, 12
step: GCD of 24 and 36 is 12

greatest-common-divisor The GCD of two numbers is the largest factor they share. List every factor of each number, then circle the ones that appear on both lists. The biggest circled number is the GCD. It tells you the largest piece both numbers can be evenly divided into.