Calcul (nombres naturels)

$$\begin{array}{rrrrrr} & {\small\color{red}{1}} & {\small\color{red}{}} & {\small\color{red}{}} & {\small\color{red}{}} & {\small\color{red}{}}\\ & & 9 & 1 & 2 & 2\\ + & & 3 & 8 & 7 & 5\\ \hline & 1 & 2 & 9 & 9 & 7\\ \end{array}$$

Nouvel exemple