Author note — to cover

Cover percentage change as change divided by original times 100, rises and falls, calculator and simple non-calculator cases, changes beyond 100%, and the dividing-by-the-new-value error. Expressing one quantity as a percentage of another in general is Number's FDP work; profit wording and fair comparisons are the sibling pages. Both tiers. (R9)

• Fluency — direct questions on measuring a change as a percentage, 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).