These durable, double-sided flash cards are great for home or classroom use. They have problems on both sides with the answers in small print on the reverse side of each card. They feature a hole in the top corner that can be fit with a ring or string for easy organization and storage. Additionally, one corner is shaped differently than the others, making it easy to face all of the cards in the same direction. Includes 56 cards (featuring 91 problems), each measuring 3 1/8" x 5 1/8", and instructions and tips for teachers or parents. For ages 8 and up