$ \text{Gegeben:}\\\text{Seite} \qquad a \qquad [m] \\ \\ \text{Gesucht:} \\\text{Fläche} \qquad A \qquad [m^{2}] \\ \\ A = a^{2}\\ \textbf{Gegeben:} \\ a=\frac{1}{5}m \qquad \\ \\ \textbf{Rechnung:} \\ A = a^{2} \\ a=\frac{1}{5}m\\ A = (\frac{1}{5}m)^{2}\\\\A_{q}=\frac{1}{25}m^{2} \\\\\\ \small \begin{array}{|l|} \hline a=\\ \hline \frac{1}{5} m \\ \hline 2 dm \\ \hline 20 cm \\ \hline 200 mm \\ \hline 2\cdot 10^{5} \mu m \\ \hline \end{array} \small \begin{array}{|l|} \hline Aq=\\ \hline \frac{1}{25} m^2 \\ \hline 4 dm^2 \\ \hline 400 cm^2 \\ \hline 4\cdot 10^{4} mm^2 \\ \hline 0,0004 a \\ \hline 4\cdot 10^{-6} ha \\ \hline \end{array}$