Better than traditional flash cards, Number Bond cards take students beyond just practicing math facts. They illustrate the relationships between numbers as well as the inverse relationship between addition and subtraction. Students work with these 5" x 5" activity cards to build fluency, and gain number sense at the same time. Teachers can use the cards with groups, in pairs or with individuals. Answers are on the flip side of the card, so it's easy for students to check their own or each other's work. Easy to differentiate, too! 80 two-sided cards in set.