Number

Number is a unit or a symbol that forms part of a system of counting and calculating, and that represents an amount or position in a series.

The most basic examples are the natural numbers 1, 2, 3, 4, 5, 6, 7, 9, 10, 11……and so on.

In mathematics, the notion of number has been extended over the centuries to include zero (0) negative numbers (-1, -2, -3) rational numbers such as one half (1/2) or $\left({\tfrac {1}{2}}\right)$ , real numbers that can be used to measure such as distances or temperature, the square root of 2 $\left({\sqrt {2}}\right)$ and π (3,14) etc.