I really got into making math centers last year when I was teaching a 1/2 combo because I needed engaging material to keep m second graders busy while I was teaching a lesson to my first graders. I haven't looked back since! I keep an area in the back of my room with all of our math manipulatives, supplies, and games. When kiddos finish their independent practice, they go grab a math center. They're perfect to reinforce what we're doing in class. Plus, I include centers that review skills we've already done so we're continuously spiraling.