(This post is Part 2 in a series. Part 1.)
From making their balancing crayfish, students learned that adding weight to an object makes it more stable, particularly when the weight is distributed more towards the bottom than the top. Having learned this, they moved on to making tops.
Building a Top
Students began by trying out store-bought tops, then moved on to the design phase of making their own tops. Students learned that “designing is planning with purpose.” In planning, students tried to answer: “What parts am I going to use, and why?”
These are some of the materials students thought might be helpful for making their tops (for both function and decoration):
- Popsicle sticks
- Hot glue
- Paper clips
- Tin foil
Then students began building. They worked on their tops for about 30 minutes, once a week, for several weeks.
When students were stuck, they were encouraged to walk around the classroom to see what ideas their friends had come up with. I had a chance to talk with several of the students about their ideas. Many seemed focused on decorating their tops (often with Popsicle sticks) before they’d gotten them to work.
In general, students were in agreement that adding pennies for weight was necessary. Most students lined their cups with pennies, but gluing/taping them in was problematic. I asked one student if he tried securing them to the outside, but he was adamant that that would not work—that they had to be on the inside. (Maybe he’s right!—but I don’t think he ever tried it the other way, despite my encouragement.)
Students also seemed to get stuck with the idea that they had to keep adding to their designs, rather than subtract. They repeatedly told me that “shorter tops” would work better, but their designs continued to grow taller and more complex—I think because adding materials and complexity felt more creative, and more like engineering (and therefore more productive).
After several classes, students began realizing they could trim their cups down, and that made it easier to secure pennies lower. By the end, some of our students were on their way to making tops that could spin for several seconds!