This document discusses square numbers. A square number is the result of multiplying a number by itself. The area of a square is equal to the side length squared. Properties of square numbers include: being even if the number of trailing zeros is even; squaring an even number yields an even number while squaring an odd number yields an odd number; and the unit digit of a number squared equals the unit digit of the digit at the ones place squared. The document provides examples of square numbers and lists 10 properties of square numbers. It concludes by asking students to enumerate the special square numbers between 0 and 900.