10) Short sample micro-lesson (45 minutes) — topic: density (ages 11–12, concrete-operational)

1. Hook (3 min): Show two identical-looking blocks; one floats, one sinks — what’s up?
2. Advance organizer (2 min): Quick diagram showing mass, volume and density.
3. Activate prior knowledge (5 min): Pair-share: “Where have you seen floating vs sinking?”
4. Concrete lab (12 min): Measure mass and volume of small objects; compute densities (guided worksheet with steps).
5. Reflect (5 min): Groups discuss patterns and write one rule.
6. Abstract (8 min): Teacher links group rules to formal density definition; models problem with a worked example.
7. Application (5 min): Short problem: “Will this wooden block float in salt water? Explain.”
8. Exit ticket (2 min): One sentence explaining density + one question they still have.

Assessment: Quick formative feedback during lab; collect exit tickets to plan next lesson (spacing: retrieval quiz on density next week, plus interleaved problems with buoyancy).