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Types of greatest common factor worksheets you can make
GCF of two numbers: like GCF(24, 36) = 12
GCF of three numbers: like GCF(18, 30, 42) = 6
Listing factors: list the factors of each number, circle the common factors, then write the GCF. For 12 and 18, the common factors are 1, 2, 3 and 6, so the GCF is 6.
Prime factorization: write each number as a product of primes, then multiply the common primes. For example, 84 = 2 × 2 × 3 × 7 and 90 = 2 × 3 × 3 × 5, so the GCF is 2 × 3 = 6.
Venn diagrams: write the prime factors of each number in two overlapping circles, with the common factors in the middle, then multiply the middle numbers to find the GCF
Square tiles in a rectangle: find the largest square tile that covers a rectangle with no gaps, and how many tiles it takes. For example, a 20 yd by 12 yd rectangle needs 15 tiles that are 4 yd by 4 yd.
GCF of monomials: like GCF(12x²y, 18xy³) = 6xy, with two or three monomials and up to three variables
Make each worksheet your own:
four difficulty levels, from numbers up to 30 to numbers up to 200
include some pairs with a GCF of 1, like 8 and 15, so students learn to spot numbers with no common factor other than 1
choose how many problems to include
every worksheet comes with an answer key that shows the steps, with common factors circled and primes in the Venn diagram filled in