Are you ready to build a quick marble run with this low-prep STEM challenge! Let’s turn simple materials into an exciting marble run. The very first time I pulled out foam tubes and marbles and mentioned roller coasters, I knew my students were hooked on STEM forever. That challenge is their very favorite and it’s one they ask to repeat all the time. It’s a fun one, but in my mind, I always wanted to create a different kind of roller coaster. Could we try something with tubes? So, one day I gathered together a bin of cardboard tubes and rolls of masking tape, and we got to work! You Need 3 Things for the Marble Runs That’s all. Seriously. Okay, ask parents to send in the cardboard tubes from toilet tissue rolls and paper towel rolls. If you really want to get a ton of these, just mention that this is material they can send in and IT’S FREE!