Sorry for the shiny pic!! I have 5 different centers: Activities (manipulatives) Computers, Folder games, iPads, and Library.
I have 1 or 2 students at each center a day. I alternate the name cards down daily.
This is the list that I have on my board. I change it when I see that a student is struggling or excelling!
For SBC: S is for Savario (come and see me at my reading table), B is for boardwork, and C is for Centers!
To change my groups, I use a whistle like this (below) I purchased it at Cracker Barrel!