A perfect square is any integer that is the square of another integer. For instance 16=4*4 hence 16 is a perfect square, however 8 isn't one.

This is a number you can square root and come out with a whole number. 4 is a perfect square because it can be square rooted to 2. Another way to think about it is if you are trying to make squares composed of other little squares. If I want my big square to have four little squares on each side, I will have 16 little squares to make the square. We can do the reverse by taking the big whole square and dividing it by the number of little square on one side. When we do so, we will come out with an answer that matches the number you were dividing with. :) I hope this didn't confuse you too much. An AP Math student