Prices for guidance only; your local distributor will send you a quotation in your local currency.
2 / ? = 20 or ? / 10 = 20 or 2 / 10 = ? You decide! 100 bones printed black on yellow for optimum visual clarity, with a special plastic slider that conceals any one part of the number sentence at a time. Each set contains all the equations from 1 / 0 = 0 to 100 / 10 = 10.