These brightly colored, customizable cards help develop children’s study skills from a young age—as they master math facts, memorize speeches, learn vocabulary words, pick up a new language and more! Each card has a hole punched in one corner—just loop them through the included book ring to keep them together. Each pack includes 100 durable, unruled 2" x 3" or 3" x 5" cards in up to 12 vivid colors, plus a 1 3/4"-diameter book ring.