The square root of a number 'a' is number which when multiplied by itself gives that number 'a' as product. i.e., b is the square root of an if and only if a is the square of b. To find, a number whose square is known is known as finding the square root. Finding the square root of a number is the inverse operation of squaring that number. Remember, the square of a number is that number times itself. The perfect squares are the squares of the whole numbers. The square root of a number, n, written below is the number that gives n when multiplied by itself. The square is the same as the power of 2. All square numbers end with 0, 1, 4, 5, 6 or 9 at units place.