8th Grade · The Number System

Perfect Square

8.EE.A.2 · 8.NS.A.2

Definition

A number that equals an integer multiplied by itself. The square root of a perfect square is a whole number.

Examples

  • 16 is a perfect square because 4×4=16.
  • 20 is NOT a perfect square — √20 ≈ 4.47, irrational.

Key rule

The square root of a perfect square is always a whole number.

Memory hook

A whole number times itself.