Explain at three levels
ProblemExplanations are pitched too high or too low for the person asking.
Compound interest
Simple: like a snowball rolling downhill — it picks up more snow because it's already bigger.
Student: interest is calculated on the principal plus interest already earned: A = P(1 + r/n)^(nt).
Check: ₹1,000 at 10% a year for 2 years — ₹1,210, not ₹1,200.
Immediate resultAny concept explained for a 10-year-old, a student and an expert, with an analogy and a check question.


