Listing out a few elements of the set of perfect squares, we get the following values
{1, 4, 9, 16, 25, 36, 49, 64, 81, 100, ...}
we can stop there because 82 is between 81 and 100
So if x^2 = 82, then x^2 is between 81 and 100 meaning
81 < x^2 < 100
apply the square root to all sides of the compound inequality and we get
9 < x < 10
So the square root of 81 is between 9 and 10
Answer: the value falls between 9 and 10