Square Number — 9² = 81 — free printable diagram

What is 9 squared?

9 squared is 81. Squaring a number means multiplying it by itself, so 9² = 9 × 9 = 81. Read the other way round, the square root of 81 is 9.

Calculation

9² = 9 × 9

Answer

81

In words

eighty-one

Square root

√81 = 9

Position

the 9th square number

• Squaring means multiplying a number by itself, so 9² = 9 × 9 = 81.
• 81 is called a square number because 81 counters can be arranged in a perfect square of 9 rows with 9 in each row.
• The opposite of squaring is taking the square root, so √81 = 9.
• 9 squared is not 9 × 2. 9 × 2 = 18, but 9² = 81.
• Each square number is the odd numbers added up in order: 81 − 64 = 17, so the gap from 64 to 81 is 17.