A set of Ten Frame flash cards to use with your students. Number sense is one the most important concepts we can use to help build a foundation for future years in math. Copy these on card stock or heavy paper and use as flash cards. You can have the children tell you the number, tell you the number missing, give you addition and subtraction sentences using the cards, put them in a center and have the children write number sentences to go with the cards. The possibilities are endless.