Try to make sure that two weak students are not paired. Each student in a pair will select to be either number one or number two. Each pair should sit together, with the other pair that completes their team either behind or in front of them. Student working a problem explains his method orally as he works on the problem. When number one's problem is complete, the paper is passed to number two.
Number twos work their problem while the number ones coach.
Once the pair has completed one problem each, they can turn to check their answers with the other pairs in the team. If students agree, celebrate with a high five or team handshake, then go on to the next problem. Repeat until done or time is called. If students do not agree, they continue to work on the problem to get the correct answer. If they need teacher help, all will raise their hand.