Square root

The square root of a number is a number which multiplied by itself, gives you the original number. Its symbol is called a radical and looks like this: . You can usually find a key on your calculator that looks like this.
For example, is 3, because 3 x 3 = 9.

Here are a few other square roots:
The is 4 because 4 x 4 is 16

The is 5 because 5 x 5 is 25
Now, here's a problem for you:
What is the square root of 81?

Square roots can get messy if the answer is not an integer.
For example, the square root of 8 is 2.727427. . . (it keeps going on forever!).
It is best to get these square roots with your calculator (the square root key: )

Note: There are other 'roots' other than square roots.
For example a 'third root' (or 'cube root') which is represented as ∛

So the ∛27 = 3 because 3 x 3 x 3 = 27

Note: When dealing with exponents the square root of a number is that number to the ¹⁄₂ power,
or, using x, x^¹⁄₂
So, 25^¹⁄₂ = 5.