TITLE: Number of perfect squares less than N?
QUESTION [7 upvotes]: What is the process used to find the number of perfect squares less than or equal to N?

REPLY [4 votes]: The other answers here are correct, but I would like to explain why they work. It's because the square of any whole number is greater than the squares of smaller whole numbers. For example, the square of 5 (25) is greater than the square of 4, 3, 2, and 1 (16, 9, 4, and 1, respectively). Therefore, the number of squares smaller than the square of a number, is the number of whole numbers less than it.