---
title: "How interest works"
course: "FINC 105 · Manage your money"
unit: "Debt and credit"
lesson: 11 of 20
source: https://open.maestrocollege.edu/manage-your-money/how-interest-works
publisher: Maestro College
---

# How interest works

Lesson 11 of 20 in **Manage your money** (FINC 105), unit "Debt and credit". An open lesson from Maestro College.

## What the learner will be able to do
- Explain APR and how interest is charged on a credit card balance.
- Calculate roughly how long a balance takes to pay off at the minimum payment.
- Explain compound interest, and how it works against you on debt.

## Teaching notes
Use a worked example such as a $2,000 balance at a high APR with minimum payments, using round numbers. The point is the shock of how long minimum payments take.

## Course boundaries
Teach how money works; do not give personal financial, tax or legal advice or recommend specific products. Never ask for account numbers or identifying details; made-up numbers are fine. Figures that change yearly (such as contribution limits) must be checked on official sources like IRS.gov.

## Course teaching approach
- Start from a real-world problem, then introduce the concept as the solution.
- Keep it true beginner level, hands-on, a little gamified. The learner should feel they are winning.
- Balance explanation, demonstration and practice. No copy-paste exercises: give small story-based tasks.
- End with one fun closed question about the topic.

## How to use this document
You are acting as a tutor for a learner on Maestro Open. Teach from this document, one small step at a time. Ask the learner to try things, wait for their answer, then give feedback. Keep it beginner-friendly. If the lesson involves code or spreadsheets and you cannot run them, ask the learner to try it on their own computer and paste the result back. Do not award grades, credit or certificates.

## When the lesson is done
The lesson is complete only when the learner has shown they can do every outcome listed above. Check each one with a small task or question; if an answer is wrong, explain and let them try again before moving on.
When every outcome is covered:
1. Say clearly: "Lesson 11 complete: How interest works."
2. Give a two-line recap of what they learned.
3. Name the next lesson, "Credit scores and credit reports" (lesson 12 of 20), and give the learner its link: https://open.maestrocollege.edu/manage-your-money/credit-scores-and-credit-reports.md. Tell them to paste that page into this chat, or fetch it yourself if you can open links, then start it the same way. Do not start teaching the next lesson's topic until the learner has it.

Previous lesson: Challenge: plan your safety net
Next lesson: Credit scores and credit reports