Easy to make your own addition flashcards for kiddos. two sheets (front and back), back to back, use 65 or 67 bond weight paper...cut when done copying...place in little plastic 3 inch x 4 inch sealable bags (at any Hobby Lobby/Michael's style store). Costs about 13 cents a piece to make a set. Just one more tool to give kiddos to help them learn their basic math facts. It is the right size to fit in their pocket, so they do not lose them.