%@P:exocorcp %@Auteur: d'après IREM Strasbourg \begin{center} \begin{tabular}{|>{\columncolor[rgb]{1,1,0}}*{7}{c|}} \hline \rowcolor{yellow}$\times$&&&&&&\\ \hline &21&&&&27&24\\ \hline &&&&0&&\\ \hline \phantom{15}&&&36&&&\\ \hline &&35&&&&\\ \hline &42&&24&&54&\\ \hline &&5&&&&\\ \hline &35&&&10&&\\ \hline &&&&&&64\\ \hline \end{tabular} \end{center} %@Correction: \begin{center} \begin{tabular}{|>{\columncolor[rgb]{1,1,0}}*{7}{c|}} \hline \rowcolor{yellow}$\times$&\opcopy{7}{a1}\textcolor{red}{\opprint{a1}}&\opcopy{5}{a2}\textcolor{red}{\opprint{a2}}&\opcopy{4}{a3}\textcolor{red}{\opprint{a3}}&\opcopy{2}{a4}\textcolor{red}{\opprint{a4}}&\opcopy{9}{a5}\textcolor{red}{\opprint{a5}}&\opcopy{8}{a6}\textcolor{red}{\opprint{a6}}\\ \hline \opcopy{3}{b1}\textcolor{red}{\opprint{b1}}&\opmul*{b1}{a1}{a}\opprint{a}&\opmul*{b1}{a2}{a}\textcolor{red}{\opprint{a}}&\opmul*{b1}{a3}{a}\textcolor{red}{\opprint{a}}&\opmul*{b1}{a4}{a}\textcolor{red}{\opprint{a}}&\opmul*{b1}{a5}{a}\opprint{a}&\opmul*{b1}{a6}{a}\opprint{a}\\ \hline \opcopy{0}{b2}\textcolor{red}{\opprint{b2}}&\opmul*{b2}{a1}{a}\textcolor{red}{\opprint{a}}&\opmul*{b2}{a2}{a}\textcolor{red}{\opprint{a}}&\opmul*{b2}{a3}{a}\textcolor{red}{\opprint{a}}&\opmul*{b2}{a4}{a}\opprint{a}&\opmul*{b2}{a5}{a}\textcolor{red}{\opprint{a}}&\opmul*{b2}{a6}{a}\textcolor{red}{\opprint{a}}\\ \hline \opcopy{9}{b3}\textcolor{red}{\opprint{b3}}&\opmul*{b3}{a1}{a}\textcolor{red}{\opprint{a}}&\opmul*{b3}{a2}{a}\textcolor{red}{\opprint{a}}&\opmul*{b3}{a3}{a}\opprint{a}&\opmul*{b3}{a4}{a}\textcolor{red}{\opprint{a}}&\opmul*{b3}{a5}{a}\textcolor{red}{\opprint{a}}&\opmul*{b3}{a6}{a}\textcolor{red}{\opprint{a}}\\ \hline \opcopy{7}{b4}\textcolor{red}{\opprint{b4}}&\opmul*{b4}{a1}{a}\textcolor{red}{\opprint{a}}&\opmul*{b4}{a2}{a}\opprint{a}&\opmul*{b4}{a3}{a}\textcolor{red}{\opprint{a}}&\opmul*{b4}{a4}{a}\textcolor{red}{\opprint{a}}&\opmul*{b4}{a5}{a}\textcolor{red}{\opprint{a}}&\opmul*{b4}{a6}{a}\textcolor{red}{\opprint{a}}\\ \hline \opcopy{6}{b5}\textcolor{red}{\opprint{b5}}&\opmul*{b5}{a1}{a}\opprint{a}&\opmul*{b5}{a2}{a}\textcolor{red}{\opprint{a}}&\opmul*{b5}{a3}{a}\opprint{a}&\opmul*{b5}{a4}{a}\textcolor{red}{\opprint{a}}&\opmul*{b5}{a5}{a}\opprint{a}&\opmul*{b5}{a6}{a}\textcolor{red}{\opprint{a}}\\ \hline \opcopy{1}{b6}\textcolor{red}{\opprint{b6}}&\opmul*{b6}{a1}{a}\textcolor{red}{\opprint{a}}&\opmul*{b6}{a2}{a}\opprint{a}&\opmul*{b6}{a3}{a}\textcolor{red}{\opprint{a}}&\opmul*{b6}{a4}{a}\textcolor{red}{\opprint{a}}&\opmul*{b6}{a5}{a}\textcolor{red}{\opprint{a}}&\opmul*{b6}{a6}{a}\textcolor{red}{\opprint{a}}\\ \hline \opcopy{5}{b7}\textcolor{red}{\opprint{b7}}&\opmul*{b7}{a1}{a}\opprint{a}&\opmul*{b7}{a2}{a}\textcolor{red}{\opprint{a}}&\opmul*{b7}{a3}{a}\textcolor{red}{\opprint{a}}&\opmul*{b7}{a4}{a}\opprint{a}&\opmul*{b7}{a5}{a}\textcolor{red}{\opprint{a}}&\opmul*{b7}{a6}{a}\textcolor{red}{\opprint{a}}\\ \hline \opcopy{8}{b8}\textcolor{red}{\opprint{b8}}&\opmul*{b8}{a1}{a}\textcolor{red}{\opprint{a}}&\opmul*{b8}{a2}{a}\textcolor{red}{\opprint{a}}&\opmul*{b8}{a3}{a}\textcolor{red}{\opprint{a}}&\opmul*{b8}{a4}{a}\textcolor{red}{\opprint{a}}&\opmul*{b8}{a5}{a}\textcolor{red}{\opprint{a}}&\opmul*{b8}{a6}{a}\opprint{a}\\ \hline \end{tabular} \end{center}