What is a square number?

A square number (or perfect square) is what you get when you multiply a whole number by itself. 3 × 3 = 9, so 9 is a square number. It is written with a small '2' , 3² means 3 squared. They are called 'square' because that many dots form a perfect square.

Examples

• 1, 4, 9, 16, 25 are the first square numbers.
• 6² = 6 × 6 = 36.
• The square of 10 is 100.

Quick facts

• 3² means 3 × 3, not 3 × 2.
• The square numbers to 100 are 1, 4, 9, 16, 25, 36, 49, 64, 81, 100.