Author note — to cover

Cover finding one unit's value then scaling: cost per item, exchange-rate style conversions, time for one machine, choosing between unitary and scaling-factor routes, calculator and non-calculator. Conversion here means proportional quantities; single measurement units are Number's. Recipes and best buys apply this on the sibling pages. Both tiers. (R10, R5)

• Fluency — direct questions on the unitary method, limited to this lesson's stated scope (4 questions).
• Application — use the same skill in unfamiliar or contextual questions without introducing a later method (4 questions).
• Check — questions built around the exclusions and likely misconceptions named in the lesson brief (4 questions).