SAAM Foundations.

One plain-language lesson a week on how personal finance works: budgeting, retirement accounts, accounts for children, tax-advantaged accounts, housing and estate planning. Free with an account.

Every lesson has the same five parts: what it is, how it works, a worked example, what people often get wrong, where the rules come from. Each limit and rule is given with the year it applies to and a link to its source.

1. Lesson 1How Compound Interest WorksCompound interest is interest earned on earlier interest as well as on the original amount. This lesson shows the arithmetic, what changes the result, and where the rules on quoting rates come from.Oct 12, 2026 · 4 min read

Lessons explain how things work. They are general education, not investment, tax or legal advice, and they never say what you should choose. See the full disclaimer.