Describe how you would estimate the square root of a number that is not a perfect square

You would find the closest perfect square lower than it and the closest perfect square higher than it and estimate. For example the square root of 4 is 2, but we don't know the square root of 5. We know that it must be greater than 2 but lower than 3 because the square root of 9 is 3. So it will be 2.something