I find that having assigned weekly monitors cuts down on the kids begging to be a helper. Every week I choose a clerk, a librarian, a folder monitor and a custodian. The clerk passes out papers, the librarian calls the children by row to put away their novel, the folder monitor passes out and collects folders and the custodian checks for lost items and gets the kids to pick up their trash. If someone is absent, the substitute is always the person who had that job the previous week. This cuts down on the 'pick me' clamoring. I keep a spreadsheet check list and no one can have a second monitor job until everyone has had a turn.