Goal: identify that shape and width can vary together and refuse an unsupported “shape alone” explanation. Proposed codes: AC9SFU02, AC9SFH01, AC9SFI03. Prepare: teacher-made paper plan of an 8 cm square outline and a 10 cm round outline against a 9 cm marked passage; no objects supplied, Card 57.
- Source · 3 min. Mark the two outlines INVENTED PLAN; date model use. Do not call a paper circle a real ball or say it rolled.
- Notice · 4 min. Child identifies square 8 cm across, round outline 10 cm across, 9 cm gap. Adult reads shape and width labels rather than relying on sight.
- Model · 5 min. Teacher asks, “Both shape and width changed. Which one did we hold still?” Answer: neither; a result could not isolate shape alone.
- Child try · 7 min. Card 57 routes make a cautious drawing claim and propose a matched-width, verified-material approved comparison if the school can safely supply it; no invented real outcomes.
- Check · 4 min. Offer “Round things can never pass a passage.” Child rejects the universal claim and points to missing real source, gap and object dimensions.
- Exit · 2 min. Record the next question, not a pretend trial.