A set of A5 cards designed to be used with connecting number rods using numbers 1-20 in the question. There are 10 addition and 10 subtraction color-coded cards. Each card has a question on the front and the answer with images of the connecting number rods on the reverse. Any card can be completed using the connecting number rods 64 piece set (sold separately).Details:5.8" x 8.3" (A5) card size20 cards with questions on one side and answer on reverse sideContains 10 addition and 10 subtraction questions for numbers up to 20For use with the Connecting Number Rods sets (sold separately)For ages 3 and up