Cube Control Set 3 up to 20
Cube Control Set 3 up to 20 | An unique, cheap and simple self-correcting system. Children have to find the right answer on one of the cubes on top for the exercise. They build a tower completing the exercise.
The colour sequence of the tower has to be compared with the colour sequence of the pattern on the reverse side. The exercise cards are printed on plastic.
5 double-sided cards for addition and subraction up to 20.