As my students know, I am a bit of an efficiency freak (read: I’m kind of impatient and actively organize my classroom to avoid patience problems). I love having students work with students other than the ones that sit right around them ( I don’t have assigned seats), but I can’t stand the time it takes to reorganize into groups. So whenever we do this, I do it right from the beginning of class. Students walk into the classroom to find the whiteboards laid out on the tables like this:

I usually stand around the door just instructing them to sit where their names are (even though most figure it out anyway). What usually happens is about half of the kids show up a few minutes early and sit behind the boards twiddling their thumbs. But then the problem catches their eye… And you can see them looking back and forth, fiddling with the markers, trying to resist the urge to DO MATH! Inevitably someone asks: “Mr Bowman, can we get started?” I’m like the coyest math teacher in the world, so I always respond “Uh, yeah, um sure, I guess” while my mind is deviously tapping its fingers together like Mr. Burns. Then the other kids trickle in, and immediately engage because they see someone else working (and haven’t really missed anything). Every time I do this, every single student in class is engaged in math by 30 seconds into the period with little to no cajoling from me. Then after a few minutes, I might give a few more instructions (like, this is MISTAKE GAME!) I realize that this may seem trivial/common sense, but the thing that makes me happiest is using every minute of every class!

Variations: If you don’t want to assign groups (which I usually do to get specific students working together) you can do this randomly with a deck of cards, or something similar.