GCF & LCM

Find the greatest common factor and least common multiple using prime factorization — with the reasoning shown.

1. 1

   Prime factorization of each number.

   24 = 2³ × 3

   36 = 2² × 3²

   Why?
2. 2

   GCF: multiply the shared primes, using the smaller power of each.

   GCF = 2² × 3 = 12

   Why?
3. 3

   LCM: multiply every prime that appears, using the larger power of each.

   LCM = 2³ × 3² = 72

   Why?