When students are done with their work, they are welcome to log in to IXL and work on grade level appropriate math activities. When they get 100% on a skill, they are able to cross it off on their chart. As an incentive, when they hit a milestone (25, 50, 75, 100, etc.) skills they have mastered, there is a different prize for them. For example, for the first 25 they finish they get a piece of candy and get to put their name under 25 on the cupboards. When they hit 50, they get to move their name under 50 on the cupboards and get a homework pass, which is attached. Students love to see their names move on the cupboards and competing with each other. I have also seen some teachers use IXL as homework. For example, they log the time they spent on IXL, somewhat like they would do a reading log.