Natural number

From Simple English Wikipedia, the free encyclopedia

Natural numbers are the numbers used for counting things. Natural numbers are positive numbers (numbers that are more than 0). They are 1, 2, 3, 4, 5... and so on until infinity. Natural numbers are also called Counting Numbers.

[edit] Notation

\mathbf{N} or \mathbb{N} is the way to write the set of all natural numbers. Because some people say 0 is a natural number, and some people say it is no natural number, people use the following symbols to talk about the natural numbers:

Symbol Meaning
\mathbb{N}^+ Positive numbers, with zero
\mathbb{N}^* Positive numbers without zero
\mathbb{N}_0 Positive numbers, with zero
\mathbb{N}_{>0} Positive numbers without zero
\mathbb{N} \setminus \{0\} Positive numbers without zero