Brug over tiental

Reken uit

\(7 + 14 = \ldots\)

\(\begin{align} & 7 + 14 \\= & 14 + 7 \\= & 14 + \color{green}{6} + \color{red}{1} \\= & \color{green}{20} + \color{red}{1} \\= & \color{red}{21} \end{align}\)