Calcul (nombres naturels)

$$\begin{array}{rrrrrr} & {\small\color{red}{}} & {\small\color{red}{1}} & {\small\color{red}{1}} & {\small\color{red}{}}\\ & 1 & 4 & 7 & 8\\ + & 2 & 4 & 2 & 8\\ \hline & 3 & 9 & 0 & 6\\ \end{array}$$

Nouvel exemple