Brug over tiental

Reken uit

\(62 + 9 = \ldots\)

\(\begin{align} & 62 + 9 \\= & 62 + \color{green}{8} + \color{red}{1} \\= & \color{green}{70} + \color{red}{1} \\= & \color{red}{71} \end{align}\)