I use a Bingo grid to encourage my students to do their homework. The grid is a 5 x 5 square with one side numbered 1-5 and the bottom lettered A-E. Each square corresponds to one of the homework questions. I also make 25 cards that correspond to the squares on the grid. On the day that homework is due, I make this BINGO grids and pass them out, shuffle the cards, and begin the game.
I pull the top card from the stack and call the combination (e.g., D-3). If a student has completed the homework question, I initial that square. They get a reward when they get five in a row. If someone wins, that student gets a new grid, but the others keep theirs until they earn a reward.