What is a whole number? Simply put, whole numbers are numbers that are not fractions. Although the definition of whole numbers seems simple, it is an extremely important number sense skill for kids to learn at an early age. Turtle Diary designed a whole numbers game to help kids understand what whole numbers are and how they are applied to real situations in life. Our whole numbers game uses actual examples and fun pictures to explain whole numbers in a way that kids can really understand and retain for future math lessons.