What Is a Perfect Square?

The second power of an integer: 0, 1, 4, 9, 16, 25... are perfect squares.


A perfect square is a number we get when we multiply an integer by itself.


For example:

  • 1 × 1 = 1
  • 2 × 2 = 4
  • 3 × 3 = 9
  • 4 × 4 = 16
  • 5 × 5 = 25


The numbers 1, 4, 9, 16, and 25 are all perfect squares because they are the result of squaring an integer.


We can also write perfect squares using exponents:

  • 3² = 9
  • 6² = 36


Perfect squares are closely connected to square roots. If 25 is a perfect square, then √25 = 5.


We use perfect squares when:

  • Finding the area of a square
  • Working with square roots
  • Solving quadratic equations


When Do Students Learn About Perfect Squares?

Students begin learning about perfect squares when they study multiplication and exponents.


Grades 4–5 – Introduction to Squaring Numbers

Students recognize square numbers through multiplication facts and area models.


Grades 6+ – Using Perfect Squares in Algebra

Students use perfect squares when working with exponents, square roots, and solving equations.

Video Guides Related to Perfect Squares

Math Terms Related to Perfect Squares

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