√100 = 10. The square root of 100 is 10, because 10 × 10 = 100. 100 is a perfect square.
√100 at a glance.
Value
10
Rounded
10
Perfect square?
Yes
100 squared
10,000
Checking it in your head
A perfect square's root is a whole number, so check by multiplying back: 10 × 10 = 100. Its last digit fits too: squares only ever end in 0, 1, 4, 5, 6 or 9, and 10² ends in 0.
Frequently asked questions
What is the square root of 100?
The square root of 100 is 10, because 10 × 10 = 100. 100 is a perfect square.