Children learn the dynamics of multiplication and division through visual aid. Each set of double-value flash cards in vertical format includes 90 cards: 81 cards printed on two sides, one side printed with a multiplication problem and the other side with a directly related division problem (e.g. 3x1=3 on one side, 3÷3=1 on the reverse), plus suggested activities cards. For every multiplication fact, there are three other facts that belong to the same family. Sold as 2 sets for a total of 180 cards.