**A whole number belongs to the set of integers that are equal to or greater than zero.** For example, the set of numbers {0, 1, 2, 3, 4, 5, ...} contains all of the whole numbers.

Negative numbers and decimals are not considered whole numbers, although negative numbers are considered integers. The set for integers can be written as { ... -3, -2, -1, 0, 1, 2, … }. A counting number is any whole number except for zero and is shown by the set {1, 2, 3, 4, 5, … }. The term "natural number" may refer to either the set of whole numbers or the set of counting numbers.