Understand the method

Guides

Concise, original explanations that help you understand formulas, compare assumptions, and use results responsibly.

Understand compounding periods, contributions, effective growth, and why assumptions matter.

Build a fair rent-versus-buy comparison that includes cash flow, equity, risk, and flexibility.

Learn the denominator that makes margin and markup different, with worked examples.

Choose useful criteria, weight them consistently, score evidence, and test sensitivity.