Subtraction buddy

Self-checking material to learn the subtractions up to 20. One side of the card features anchor sums, whereas the other side contains mixed sums. The sums have been printed in green and the answers in red. Place the red card on top of the card with sums to hide theanswers.

Contents:
10 plastic cards
4 red transparent plastic cards
plastic box (8 x 4.5 x 1.8 cm)