Deccimal Approximations of Square Roots - Concept

We know certain square numbers: 2 squared is 4, 3 squared is 9, 4 squared is 16, etc, so we can also know some square roots: the square root of 4 is 2, square root of 9 is 3, square root of 16 is 4. What about finding the square roots of numbers that are not perfect squares- like the square root of 10? There is a number that, when multiplied by itself gives us 10- it's just not an integer. Since the square root of 9 is 3, the square root of 10 must be just over 3, like maybe 3.1 . We can use the perfect square numbers that we do know to approximate other square roots.