Print and laminate. Use poster cards to hang in the classroom. Have students complete the paper copy (printable) first. Choose from 3 versions. Students will work in pairs, or on their own to choose a problem and solve it with a dry erase marker. As a class, visit each problem and discuss how it was solved. Or place cards on binder rings, and use as independent or partner work at your math station. 16 addition and subtraction problems. Answer key included.