Goal: revise a duration claim when two start-together events have the opposite stop order. Proposed code: AC9MFM01. Prepare: Card 117, Set E with A/B stop order reversed, tactile or auditory route as chosen.
- Retrieve · 3 min. Show the prior paper diagram; child identifies why B was longer in that run.
- Model · 4 min. Start both anew and stop B first, keeping A active. Say the earlier claim must change because this run differs.
- Guide · 5 min. Children put STOP B and STOP A cards on the shared-start lanes in the order observed, then choose shorter/longer.
- Independent try · 7 min. Adult performs another pair with changed stop order but neutral labels. Child gives both comparisons: first to stop is shorter; continuing one is longer, with reason.
- Challenge · 4 min. Ask whether a paper marker that moved less could still be active longer. Demonstrate slow continued motion; duration is not distance/speed.
- Exit · 2 min. Ask “What would you look or listen for next time?” If only a colour or amount is cited, re-observe two stops tomorrow.