7th Grade · Expressions & Equations

Greatest Common Factor

7.EE.A.1

Definition

The largest factor shared by two or more numbers or terms. Used to simplify fractions and factor algebraic expressions.

Examples

  • GCF of 12 and 18 is 6 (common factors: 1, 2, 3, 6).
  • GCF of 4x and 6x² is 2x, so 4x + 6x² = 2x(2 + 3x).

Key rule

GCF is used to factor expressions — pull it out.

Memory hook

The biggest number that divides them all.