Self-control material for learning subtraction by age 20.
One side of the card contains anchor totals, the other mixed totals. The totals are printed in green and the answers are printed in red. The red card is placed on top of the card with the totals to cover the answers.
The children place the red templates on the cards and calculate. When you pull the template down, the red solution number becomes visible for immediate self-checking.
Scope:
10 plastic cards
3 red transparent plastic cards
Plastic box (8 x 4.5 x 1.8 cm)