Paint chips. *I use pairs of these to pair up my students in class. They draw them out of a bag, find their match & then work together. I let the "true Mickey Mouse" ears (black pairs) get first pick of materials or place to sit.
When you say "fist to five check" students rate their understanding by holding up the appropriate number of fingers. The goal is for everyone to be in the green. Great way for students to self-assess their understanding and help you to gauge student understanding.