The Great Marble Sorter
The Great Marble Sorter https://docs.google.com/document/d/1-ROKPv6xPrWZmZWfFLJ1uQatONpGUZtOxDXhJq64Jnc/edit Days: 2 Mode: Pairs Take-home: Working gravity-powered sorter
Teaching & key ideas
Key concepts: Size/shape classification, gravity, ramps, constraints, reliability, systems engineering.
Hook: Drop mixed objects through a sample sorter and reveal separate outputs.
Test / evidence: Sorter correctly separates a mixed test set repeatedly.
Variables to change: Opening size; ramp angle; guide-wall geometry; object spacing.
Lesson flow
Lesson plan:
Day 1: Study test objects → sketch sorting sequence → build
Day 2: Run standardized test set → diagnose failures → redesign → final accuracy test
Safety / cleanup:
Marbles counted in/out; keep off floor; teacher handles cutting/hot glue.