Calcul (nombres naturels)

$$\begin{array}{rrrrrrr} & {\small\color{orange}{}} & {\small\color{orange}{}} & {\small\color{orange}{}} & {\small\color{orange}{1}} & {\small\color{orange}{2}} & {\small\color{orange}{1}}\\ & {\small\color{blue}{}} & {\small\color{blue}{}} & {\small\color{blue}{}} & {\small\color{blue}{2}} & {\small\color{blue}{3}} & {\small\color{blue}{2}}\\ & {\small\color{red}{}} & {\small\color{red}{}} & {\small\color{red}{}} & {\small\color{red}{}} & {\small\color{red}{1}} & {\small\color{red}{}}\\ & & & & & 3 & 4 & 3\\ \cdot & & & & & \color{orange}{6} & \color{blue}{8} & \color{red}{3}\\ \hline & & \color{red}{} & \color{red}{} & \color{red}{1} & \color{red}{0} & \color{red}{2} & \color{red}{9}\\ & & \color{blue}{} & \color{blue}{2} & \color{blue}{7} & \color{blue}{4} & \color{blue}{4} & \color{blue}{0}\\ + & & \color{orange}{2} & \color{orange}{0} & \color{orange}{5} & \color{orange}{8} & \color{orange}{0} & \color{orange}{0}\\ \hline & & 2 & 3 & 4 & 2 & 6 & 9\\ \end{array}$$

Nouvel exemple