Using desk icons allows you classroom management and instructional opportunities. These icons are designed for a class of up to 28 students sitting in groups of 4. I added another 4 just in case. I would recommend printing them on card stock.
These will allow you to get students into...
7 groups of 4 by number
7 groups of 4 by icon (these are based on Emoji Icons)
4 groups of 7 by color
You can do this all in the same lesson! Start group work by table number. Then re-sort by icon. At their new group, have students share what they discussed/learned in the previous group. This will expand their understanding, but also get them moving. Finally, get students into 4 main groups to summarize key learning and come up with the big idea -- good closure!
Beyond instructional implications, these icons provide support with classroom management. You can ask a specific color at each table to get or collect materials. You can dismiss by icon. No more arguing...okay, so maybe this won't eliminate all arguing, but these provide you with a random way so no one feels like they are being singled out. It will save time so that you can get right down to learning.
Although these were designed to be taped to student desks (use packing tape!), you could also just use them as grouping icons passing them out whenever you plan on doing cooperative work.
These can also be used for staff development. Get the staff talking to different people while modeling good instruction at the same time!