What set of natural numbers is less than or equal to 8?

The set of natural numbers that is less than or equal to eight is {0, 1, 2, 3, 4, 5, 6, 7, 8}. A natural number is zero or any whole positive number. The numbers zero through seven are included because they are less than eight and fit the definition.

Eight is also included because it is a whole positive number, and it is equal to eight. Negative numbers are less than eight, but they are not natural numbers. Many fractions are less than eight in value, but they aren't whole numbers, which excludes them from the set. This is a closed set with a specific beginning and a specific end.