Showcase: Tree-House Delivery Day
Inventors (Intermediate), mission I7 Pulleys & Belts, lesson 6 of 6.
Hook
Every team delivers the basket while the spring scale shows its pull.
Fair test
Three official tries against the criteria. The Recorder writes every result on the scoreboard.
Bonus challenge
Award the “Smooth Operator” for the gentlest, least-swinging lift.