Bilangan rasional

Natural numbers ($\mathbb{Q}$, quotient = hasil bagi)

$\mathbb{Q} = \lbrace \frac{m}{n} : m, n \in \mathbb{Z} , n \neq 0 \rbrace$

$\mathbb{Z}$ : Bilangan bulat

Desimal

Bilangan rasional memiliki karakteristik desimal berulang.

$\frac{1}{9} = 0,11111... = 0,\bar{1} \\ \frac{1}{2} = 0,50000... = 0,5\bar{0} \\ \frac{3}{7} = 0,272727... = 0,\overline{27} \\$