This problem begins with a video of stacking two different sized cups (styrofoam and Solo) and asks students to figure out where the cups will tie. Students make a few estimates and then have to consider what would be useful to know about the situation in order to answer the question. They work on the problem and present their reasoning  and then watch a video to see who came closest. This problem, like the Dan Meyer version, allows students to see the effect of rate of change and starting amount on a function over time. It also lends itself to an interesting conversation about real-world math as students discuss what might account for the fact that they were not exactly right.

For extra support – here’s a video of Andrew doing this task with a group of teachers