Can a sheet of aluminum foil — a material that sinks flat — be shaped into a boat that holds dozens of paperclips?That's the question students tackle in this hands-on engineering design lab. They design two different foil boats, predict which will hold more mass, test them head-to-head, record data, and write a rigorous evidence-based reflection connecting their results to density, volume, buoyancy, and hull design. It's one of the most memorable labs of a density unit — and it fits in a single