# Difference between revisions of "Integer"

An integer number is one of the numbers obtained in counting (positive integers also known as natural numbers): $1,2,3,\dots$, zero: $0$, or one of the negative integers: $\displaystyle -1,-2,-3,\dots$. If $\displaystyle{a}$ and $b$ are integers, then so is their sum $a+b$, their difference $\displaystyle a-b$, and their product $ab$, but their quotient $\frac ab$ may or may not be an integer.

The class of integers is the simplest class of numbers and is used to construct other classes like rational numbers and real numbers.