A square root of a number is a value which when multiplied to it self gives you the original number. The square roots of perfect squares are whole numbers. Like square root of 9 is 3, because 3 times 3 is 9. Similarly square root of 81 is 9 because 9 times 9 is 81. Others numbers do not have a perfect square root and in those cases you can only simplify the number to an extent. So to find out the square root of any number first you need to factorize that number. Factorize the number into smallest possible fractions. Now when you have two number of the same factor you can pull it out of the square as a single number. In this way bring all the possible numbers out of the root leaving the square root quantity in its simple terms. This video shows how to simplify square roots of any numbers.