Popular, self-checking and fun—these three-corner flash cards are a great way to master multiplication and division through 12! The unique, three-sided cards teach not just the operations, but also the relationship between them. Each side of a card features three numbers—kids multiply the two red numbers…divide the purple number by a red number…and discover that the product or quotient is the third number on the card! Great for use at home or in the classroom and for small-group or individual practice, the set includes 46 durable, double-sided cards in a handy reusable container; each card measures 5 1/2".