%@P:exocorcp
%@Auteur: d'après IREM Strasbourg
\begin{center}
  \begin{tabular}{|>{\columncolor[rgb]{1,1,0}}*{7}{c|}}
\hline
\rowcolor{yellow}$\times$&&&4&&&\\
\hline
9&&&36&&&\\
\hline
5&&&20&&&35\\
\hline
\phantom{15}&&56&&63&&\\
\hline
&48&&&&16&56\\
\hline
&&&16&&&\\
\hline
6&&48&&&&\\
\hline
  \end{tabular}
\end{center}
%@Correction:
\begin{center}
  \begin{tabular}{|>{\columncolor[rgb]{1,1,0}}*{7}{c|}}
\hline
\rowcolor{yellow}$\times$&\textcolor{red}{6}&\textcolor{red}{8}&4&\textcolor{red}{9}&\textcolor{red}{2}&\textcolor{red}{7}\\
\hline
9&\opmul*{9}{6}{a}\textcolor{red}{\opprint{a}}&\opmul*{9}{8}{a}\textcolor{red}{\opprint{a}}&36&\opmul*{9}{9}{a}\textcolor{red}{\opprint{a}}&\opmul*{9}{2}{a}\textcolor{red}{\opprint{a}}&\opmul*{9}{7}{a}\textcolor{red}{\opprint{a}}\\
\hline
5&\opmul*{5}{6}{a}\textcolor{red}{\opprint{a}}&\opmul*{5}{8}{a}\textcolor{red}{\opprint{a}}&20&\opmul*{5}{9}{a}\textcolor{red}{\opprint{a}}&\opmul*{5}{2}{a}\textcolor{red}{\opprint{a}}&35\\
\hline
\textcolor{red}{7}&\opmul*{7}{6}{a}\textcolor{red}{\opprint{a}}&56&\opmul*{7}{4}{a}\textcolor{red}{\opprint{a}}&63&\opmul*{7}{2}{a}\textcolor{red}{\opprint{a}}&\opmul*{7}{7}{a}\textcolor{red}{\opprint{a}}\\
\hline
\textcolor{red}{8}&48&\opmul*{8}{8}{a}\textcolor{red}{\opprint{a}}&\opmul*{8}{4}{a}\textcolor{red}{\opprint{a}}&\opmul*{8}{9}{a}\textcolor{red}{\opprint{a}}&16&56\\
\hline
\textcolor{red}{4}&\opmul*{4}{6}{a}\textcolor{red}{\opprint{a}}&\opmul*{4}{8}{a}\textcolor{red}{\opprint{a}}&16&\opmul*{4}{9}{a}\textcolor{red}{\opprint{a}}&\opmul*{4}{2}{a}\textcolor{red}{\opprint{a}}&\opmul*{4}{7}{a}\textcolor{red}{\opprint{a}}\\
\hline
6&\opmul*{6}{6}{a}\textcolor{red}{\opprint{a}}&48&\opmul*{6}{4}{a}\textcolor{red}{\opprint{a}}&\opmul*{6}{9}{a}\textcolor{red}{\opprint{a}}&\opmul*{6}{2}{a}\textcolor{red}{\opprint{a}}&\opmul*{6}{7}{a}\textcolor{red}{\opprint{a}}\\
\hline
  \end{tabular}
\end{center}