After doing many factoring and distributing rectangle problems, it is helpful to review what was accomplished in a classroom discussion such as the one in this video, prior to introducing the division problems. If you haven't yet, you should practice some 3D problems. While their curricular payoff may not be quite as immediate as the basic rectangle problems, they do help to deepen understanding and to increase motivation. This video wraps up our initial work with the corner piece. This is the most basic and most important use of the Lab Gear. We'll return to the corner piece when we tackle "advanced" Lab Gear topics (completing the square, simplifying algebraic fractions).