What is the square root of 6.25?

The square root of 6.25 is 2.5.
The square of 2.5 is 6.25. The easiest way to find the square root of a number without a calculator is factoring, and finding perfect squares within your answer. In this example, you can just move the decimal place to the right two places, and factor the resulting 625. Since 25 x 25 = 625, all that is left is to move the decimal back over and you are left with an answer of 2.5.