Calcul (nombres naturels)

$$\begin{array}{rrrrrr} & {\small\color{red}{1}} & {\small\color{red}{1}} & {\small\color{red}{}} & {\small\color{red}{}}\\ & 2 & 8 & 9 & 1\\ + & 5 & 7 & 6 & 7\\ \hline & 8 & 6 & 5 & 8\\ \end{array}$$

Nouvel exemple