Calcul (nombres naturels)

$$\begin{array}{rrrrrr} & {\small\color{red}{}} & {\small\color{red}{8}} & {\small\color{red}{16}} & {\small\color{red}{}}\\ & 2 & \color{gray}{9} & \color{gray}{6} & 5\\ - & & 3 & 9 & 4\\ \hline & 2 & 5 & 7 & 1\\ \end{array}$$

Nouvel exemple