Display lottery game board on clear touch or make your own chart with numbers (you can add more numbers, or take numbers off depending on how many students/questions you have).
Students then solve a set of problems/questions, individually or in groups. As students solve a problem, they have the teacher check it. If they are correct, they can write their initials on a number or their choosing on the hundreds chart. They go back and work on another problem. When they solve that one, you check it, and if they are correct, they can write their initials on another number. (You can vary this up; for example, you could have students answer three questions or a full page and then you check and then they can put up their initials on the hundreds chart).
At the end of the time period, you then use a spinner wheel to pick numbers. The students who initialed the number picked by the spinner wheel receives a prize, or kudos, or whatever you wish to reward students with. You can choose as many winners as you want.
Easy way to gamify any assignment! Here is a video of a teacher explaining how they play this game.
Click here for powerpoint of the gameboard, or click here for an easinote file of the gameboard that you can download and save on your clear touch.