A recurring decimal has a digit or block that repeats forever. In dot notation, one dot above a digit means that single digit repeats, while dots above the first and last digits show a whole block repeats.

For example, $0.7\dot{2}=0.7222\dots$ but $0.\dot{2}1\dot{6}=0.216216\dots$. Our aim is to write these exact decimals as exact fractions, not rounded approximations.