A pair of cards is placed in the box, the blue one on the left, the red oneon the right side.
The tasks are solved by matching the magnetic symbols.
In order to check the answers the red card is turned around.
In some sets such as S1 "Nature Study" there may be tasks which you are notable to solve yet. For example you don't know how violas look like. In order to find the correct answer you go ahead as follows:
Put the answer card into the red field of the control box, the side with thesymbols on top. Match the magnetic symbols to the answer card.
Turn around the card - now you can see which tasks and solutions belongtogether.