Success: use multiplication and estimation in an invented budget, then state money left and the decision limit. Prepare: model $16 per kit, 28 kits, $470 available. Codes: AC9M5N06, AC9M5N08, AC9M5N09.
- Recall · 2 min. Ask whether “about $450” is enough to say exactly how much remains from $470. Key: no.
- Model · 5 min. State the complete fictional problem. Compute
28×$16 = 28×(10+6) = $280+$168=$448;$470−$448=$22. Rough30×$15=$450checks scale, but $450 does not replace exact payment. No actual shop price or family budget is claimed. - Guide · 6 min. Try $23 per item for 17 items with a $400 fictional limit:
23×17=23×(10+7)=230+161=391; $9 remains. Ask if $39.10 could be right for 17 items near $20 each. Key: no, scale near $340–$400. - Choose · 7 min. Day 16 A/B/C route. Learner writes/points to
price × count → total → compare with given limit → money left, including the dollar unit. No discussion of real household spending. - Exit · 3 min. “If a rough estimate is close to the limit, what next?” Key: exact calculation and constraint check.
- Record · 2 min. Note if child chose the operation and interpreted the $ difference; arithmetic alone is not the whole modelling target.