Calcul (nombres naturels)

$$\begin{array}{rrrrrr} & {\small\color{red}{1}} & {\small\color{red}{1}} & {\small\color{red}{}} & {\small\color{red}{}}\\ & 2 & 8 & 3 & 6\\ + & 6 & 6 & 8 & 0\\ \hline & 9 & 5 & 1 & 6\\ \end{array}$$

Nouvel exemple