🧪 Sensor Variable Test Sketches

Students create quick concept sketches for a simple monitor using materials and methods they could realistically test later, such as ultrasonic distance sensing, tilt triggers, timed counts, or manual calibration marks. They identify one variable to test, outline a basic algorithm for turning readings into fill-level estimates, and note feasibility constraints such as placement, cost, and durability. This just-in-time planning bridges math models to prototype decisions without building the final device yet.