Brug over tiental

Reken uit

\(25 + 6 = \ldots\)

\(\begin{align} & 25 + 6 \\= & 25 + \color{green}{5} + \color{red}{1} \\= & \color{green}{30} + \color{red}{1} \\= & \color{red}{31} \end{align}\)