Six boxes of frogs and goldfish, each with a subtraction problem underneath. The child crosses out as many as the problem takes away and counts what is left: 12 − 3 frogs, 13 − 6 fish, 15 − 7 frogs.
The first box is done as an example, with three frogs already crossed out. Having real things to cross off keeps the meaning of subtraction front and center for a child who is not ready to do it in their head.
The pictures are laid out in neat rows of five, so a child can also start to see tens and fives rather than counting one at a time.