# Rational Numbers

**Rational numbers** are integers plus fractions.

In other words number is rational, if it can be written as fraction `p/q` (we know that every integer `m` can be written as fraction `m/1`).

So, -4, -10, 0, 2, 23, `-4/5`, `-3 2/5`, `-15/7`, `2/3`, `9/4`, `5 10/11` are all rational numbers.

Thus, rational numbers include

- integers {..., -5,-4,-3,-2,-1,0,1,2,3,4,5,...}
- fractions (proper, improper, mixed numbers)

Set of rational numbers, i.e. group of rational numbers, is denoted by `QQ`.