This is a math warmup I do with my second graders. I have two seperate sheets that I've printed on two different colors and laminated, and I give each color group a number to work with for five minutes (writing with dry erase markers). For example, blue might be for my higher stduents who need a challenge, and orange might be for my students who need less of a push. Each group gets the number and completes the sheet. I have accessed some of the components of the Common Core standards for 2nd grade on these sheets. My students love them!
It could also be used as a center or whatever else you need it for!