This is not an original idea. I originally saw it on the organized teacher blog, but I needed to make mine bigger for my 1st graders to be able to use and since we are limited on copying, I decided to make it a math tub activity. Just print front to back ON CARDSTOCK, laminate and cut (note each page gives you 2 identical game sheets. After laminating, make a hole-punch in the solid square next to the answer (the back page). Students play by partnering up, facing each other, one student sees the questions (number sentences) and the other sees the answers. The student who sees the answers quizzes the other student by poking his/her pencil in the hole punch. The other student says the answer. I plan on giving my students a timer to "play" this game.