All natural numbers are whole numbers

Some authors include 0, so that the natural numbers are {0, 1, 2, 3, ...}. Whole numbers: The numbers {0, 1, 2, 3, ...}. Integers () : Positive and negative counting numbers, as well as zero:{ ..., - 2, - 1, 0, 1, 2, ...}. Rational numbers () : Numbers that can be expressed as a ratio of an integer to a non-zero integer.