The “Mobius”: Make sure the students are aware this circuit is different. It’s actually two interlocked circuits. When they finish there will be either 2, 3, 4, or 5 cells they haven’t yet used. They may pick anyone they wish and work it (labeling these cells A, B, C, D, and E as necessary). If they’ve done the primary circuit correctly these remaining cells should also form a circuit and finish the page.
The reason for this twist is that as students have become familiar with circuits it doesn’t take long for them to realize they don’t actually have to work the last two problems. This way, they’re not sure until the verification circuit how many are left and even then they need to be careful to insure they left the correct boxes.
This covers related rates, MVT, critical numbers, points of inflection and extrema.