# Difference between revisions of "Real number"

A real number is a number that falls on the real number line. It can have any value. Some examples of real numbers are:$1, 2, -23.25, 0, \frac{\pi}{\phi}$, and so on. Numbers that are not real are $\ 3i$, $\ 3+2.5i$, $\ 3+2i+2j+k$, i.e. complex numbers, and quaternions.

The set of real numbers is denoted by $\mathbb{R}$. Commonly used subsets of the real numbers are irrational numbers ($\mathbb{J}$), rational numbers ($\mathbb{Q}$), integers ($\displaystyle\mathbb{Z}$), and natural numbers ($\mathbb{N}$).

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