I usually have 6 centers going on in the room plus I select three students each day to use a computer. The students at the computer select a free online math game from our class math page or they are sent to a computer that I have loaded with software that meets their needs.
Each student has a colored dot on their desk. The dot corresponds with a center on the chart. The dots on the students desk stay the same. The center dots change every day so that a student does a different center each day. When the student gets to center on their jobs list. They get their center folder (I have them place all their center sheets in this folder. Periodically, I remove their finished work and check them. About once every two weeks.) After they finish the center and the center sheet, they place the sheet in their center folder. Next they clean up their center and put their center folder away.