The algebra expression match-up is perfect for math centers! Students match the correct expression to the corresponding word problem. The expressions are on dog bones, and the story problems are on a dog house. The file contains both a black and white version and colored version. This really helped my students with algebraic thinking. There are similar expressions in order to challenge students (example: 8-m and m-8).
I laminated my center and then added velcro to the dog house and dog bones.