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Natural Numbers

A natural number is a number used for counting things in everyday life. It is denoted as the set $\mathbb{N}$ and can be expressed as: $\mathbb{N} = \{1, 2, \dots\}.$

Remarks

Sometimes the number $0$ is included as a natural number. In order to avoid this, several notations have been created. For example $\mathbb{N}_0$ and $\mathbb{N}_1$ for the natural numbers including zero and the natural numbers excluding zero respectively.