This product as 20 strip diagrams of various strip diagram models. Students can sort the strip diagrams on whether they would add or subtract. Students can also solve the strip diagrams. To differentiate you could have higher students write a word problem to match the strip diagrams.I have also included teacher strip diagrams models. These are blank strip diagrams to help you the teacher (or maybe even the students) to make sure you are introducing every possible type of strip diagram.