Rational & Irrational numbers

Rational Numbers

A Rational Number can be written as a Ratio of two integers (ie a simple fraction).

Example: 1.5 is rational, because it can be written as the ratio 3/2

Example: 7 is rational, because it can be written as the ratio 7/1

Example 0.333… (3 repeating) is also rational, because it can be written as the ratio 1/3

Irrational numbers

But some numbers cannot be written as a ratio of two integers they are called Irrational Numbers.

π (Pi) is a famous irrational number

π = 3.1415926535897932384626433832795… (and more)

We cannot write down a simple fraction that equals Pi.

The popular approximation of ²²/₇ = 3.1428571428571… is close but not accurate.