השלימו את לוח השברים :
\begin{array}{c|c}
\hline
\times & 20 & 200 & 400 & 50 \\
\hline
{\INPUTBOX{1}{ltr}{1}}\frac{\INPUTBOX{2}{ltr}{1}}{\INPUTBOX{3}{ltr}{2}} & \INPUTBOX{4}{ltr}{30} & 300 & \INPUTBOX{5}{ltr}{600} & \INPUTBOX{6}{ltr}{75} \\
\end{array}
\hline
\times & 20 & 200 & 400 & 50 \\
\hline
{\INPUTBOX{1}{ltr}{1}}\frac{\INPUTBOX{2}{ltr}{1}}{\INPUTBOX{3}{ltr}{2}} & \INPUTBOX{4}{ltr}{30} & 300 & \INPUTBOX{5}{ltr}{600} & \INPUTBOX{6}{ltr}{75} \\
\end{array}