How do you undo squaring a number?

To square a number, you multiply it times itself, for example 3^2 = 3x3 = 9.

To "undo" the squaring of a number, you determine its square root. In this case, the square root of 9, or √9. If the number is a perfect square, then the answer is the number that you have to square to get the number under the radical, √. For instance, √9 = 3 because 3^2 = 3x3 = 9.

For numbers that are not perfect squares, or for any other number that you find difficult to work with, use your calculator. Different calculators have different keys and instructions, so you should read the instructions that came with your calculator, or look up the instructions online.