natural number

natural number (plural natural numbers)

1. (mathematics) a positive integer {1, 2, 3, ...}
2. (mathematics) a non-negative integer {0, 1, 2, ...}
   • 2007, Mark Bridger, REAL ANALYSIS: A Constructive Approach, Hoboken, New Jersey: John Wiley & Sons, page 3:

     A careful derivation of the arithmetic properties of the natural numbers ${\displaystyle \mathbb {N} }$, using induction, was done by G. Peano (1858–1932). It is a lot of fun, but we will not pursue any of it here.