81 squared

81² = 81 × 81 = 6,561

To square a number, multiply it by itself. 81 squared is written 81² or 81^2, and the answer is 6,561.

How to work out 81 squared

Direct: 81 × 81 = 6,561.
From the previous square: 80² = 6,400, and 81² = 6,400 + (2 × 81 − 1) = 6,400 + 161 = 6,561.
Split the number: 81 = 80 + 1, so 81² = 80² + 2 × 80 × 1 + 1² = 6,400 + 160 + 1 = 6,561.

Related

81 cubed = 531,441
The square root of 6,561 is 81, so 6,561 is a perfect square.

Squares near 81

Number	Squared
77	5,929
78	6,084
79	6,241
80	6,400
82	6,724
83	6,889
84	7,056
85	7,225

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