%@metapost:5fractionsexo54.mp
%@Auteur:Thierry Gauvin\par
\begin{multicols}{2}
\begin{tabular}{>\centering m{2.5cm}@{+}>\centering m{2.5cm}@{= }m{2.5cm}}
\includegraphics{5fractionsexo54.10}&\includegraphics{5fractionsexo54.10}&\includegraphics{5fractionsexo54.10}\\
$\dfrac{1}{2}$ & $\dfrac{1}{4}$ & $\dfrac{\ldots}{\ldots}+\dfrac{1}{4}=\dfrac{\ldots}{\ldots}$
\end{tabular}

\begin{tabular}{>\centering m{2.5cm}@{+}>\centering m{2.5cm}@{= }m{2.5cm}}
\includegraphics{5fractionsexo54.26}&\includegraphics{5fractionsexo54.26}& \includegraphics{5fractionsexo54.26}\\
$\dfrac{1}{4}$ & $\dfrac{7}{20}$ & $\dfrac{\ldots}{\ldots}+\dfrac{7}{20}=\dfrac{\ldots}{\ldots}$
\end{tabular}
\vspace{.4cm}
\begin{tabular}{>\centering m{2.5cm}@{+}>\centering m{2.5cm}@{= }m{2.5cm}}
\includegraphics{5fractionsexo54.18}&\includegraphics{5fractionsexo54.18}&\includegraphics{5fractionsexo54.18}\\
$\dfrac{1}{8}$ & $\dfrac{1}{2}$ & $\dfrac{1}{8}+\dfrac{\ldots}{\ldots}=\dfrac{\ldots}{\ldots}$
\end{tabular}

\begin{tabular}{>\centering m{2.5cm}@{+}>\centering m{2.5cm}@{= }m{2.5cm}}
\includegraphics{5fractionsexo54.30}&\includegraphics{5fractionsexo54.30}&\includegraphics{5fractionsexo54.30}\\
$\dfrac{1}{3}$ & $\dfrac{2}{9}$ & $\dfrac{\ldots}{\ldots}+\dfrac{2}{9}=\dfrac{\ldots}{\ldots}$
\end{tabular}
\end{multicols}
\textbf{Complète la règle :} 
\begin{center}
\psshadowbox{\begin{minipage}{0.9\linewidth}
\textit {Quand les dénominateurs sont \ldots\ldots\ldots, on ne  peut
  pas  ajouter les \ldots\ldots\ldots\ldots. On doit transformer les
  \ldots\ldots\ldots\ldots  pour  les  rendre  \ldots\ldots, ensuite on
  peut \ldots\ldots\ldots\ldots les nouveaux numérateurs.}
\end{minipage}
}
\end{center}