A number got when multiplied by itself is called a square number. Example: 3 * 3 = 9 so 9 is a square number.

0 = 0 * 0

64 = 8 * 8

49 = 7 * 7

36 = 6 * 6

So what is a perfect square? Simple way to know if a number is a perfect square or not:

- If a number ends with 2, 3, 7 ,8 at unit place then it is not a perfect square
- If a number ends with 1, 4, 5, 6, 9 in the unit place then it is definitely a perfect square

But, how to find a square root of a number? For example: what will be the **square root of 4**?

In mathematics, squaring a number is not difficult as the calculation is easy. To find the square root of a number is complicated as we need to find the original number that was squared. Let us consider an example: +5 and -5 are square roots of 25 because 5^{2} = (-5)^{2} = 25. A real number which is non negative has a unique nonnegative square root. It is called principal square root denoted by √*a*. √ is called the radical symbol or radix and in this example the principal square root of 25 is 5 which is denoted by √25 = 5, because 5^{2} = 5 • 5 = 25 and 5 is nonnegative. The number underneath the radical symbol is called the radicand. Here the radicand is 25.

**What is the square root of 4**? Considering the above example, +2 and -2 are square roots of 4 because 2^{2} = (-2)^{2} = 4. A real number which is non negative has a unique nonnegative square root. It is called principal square root denoted by √*a*. √ is called the radical symbol or radix and in this example the principal square root of 4 is 2 which is denoted by √4 = 2, because 2^{2} = 2 • 2 = 4 and 2 is nonnegative. The number underneath the radical symbol is called the radicand. Here the radicand is 4. Here is a video for shortcut method to find out the square root of a number

You can also find square root on calculator. To calculate the square root of a number online click here Square root calculator