Brug over tiental

Reken uit

\(49 + 2 = \ldots\)

\(\begin{align} & 49 + 2 \\= & 49 + \color{green}{1} + \color{red}{1} \\= & \color{green}{50} + \color{red}{1} \\= & \color{red}{51} \end{align}\)