Classroom-tested, kid-selected flash card size invites learners to pick up, play and learn. You get 169 flash cards for addition of all number families 0-12. Each two-sided flash card has:Colored borderRounded corners for durability. Pre-drilled hole for the storage ring. Bold black numbers on a crisp white background. Self-checking answer to the problem on the reverse. UV-coated cards measure 2-áx-á4". Two sort-and-store rings included with every set.