Author note — to cover

Cover compound interest year by year: interest earned on the growing balance, tabulating balances over two or three years, and the contrast with simple interest's flat additions. Small n by repeated multiplication only; the one-step power formula is the sibling page. Simple interest itself lives under Percentage change. Both tiers, since R16 does not brace compound interest. (R16, R9)

• Fluency — direct questions on compound interest, 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).