Calcul (nombres naturels)

$$\begin{array}{rrrrrr} & {\small\color{red}{}} & {\small\color{red}{}} & {\small\color{red}{1}} & {\small\color{red}{}}\\ & 5 & 3 & 1 & 2\\ + & & & 2 & 8\\ \hline & 5 & 3 & 4 & 0\\ \end{array}$$

Nouvel exemple