Many students do not go to the restroom during the scheduled break times and always seem to have to go during instruction. This is one solution. You can make each student a bathroom ticket. They get it punched each time they use the restroom during an unscheduled time. This allows students to go if they really need to, but discourages those who want to go to play in the restroom. It also rewards students who always do the right thing by giving them extra recess time. We have different recess times, so I just send those students out with another class. You can decide how long you need for each ticket. I am using one ticket for the first month, another for the rest of that grading period, and one per grading period after that. I am putting them on a poster using clothespins. I am assigning a helper to do the punches so instruction isn't interrupted. If you need yours to say something different like -5 minutes of recess instead of silent lunch, message me and I'll be happy to help.