In 'Send-a-Problem', groups of students each receive a problem, try to solve it, and then pass the problem and solution to a nearby group. Without looking at the previous group's solution, the next group works to solve the problem. After as many passes as seem useful, groups analyse, evaluate, and synthesise the responses to the problem they received in the final pass and report the best solution to the class.

'Send-a-Problem' thus involves two activity stages: solving problems and evaluating solutions. The purpose of the first stage is to provide students with an opportunity to practice together and learn from each other the thinking skills required for effective problem solving. The purpose of the second stage is to help students learn to compare and discriminate among multiple solutions.