Completed first week of school Middle School Math Rules!: The Marshmallow Challenge, a Great Team Building Exercise for introducing Math Workshop
Listening - Even though this says listening game for adults, I think it would be great for the elementary classroom as well. It gives students the opportunity to strengthen listening skills as well as cooperation skills, plus it would be fun!
Pass the Hula Hoop Team-building activity
Team building activity - Runde's Room: Introducing the Student-Led Classroom