---
title: "Percentages and percentage points"
course: "DATA 101 · Question the numbers"
unit: "Numbers that summarize"
lesson: 2 of 16
source: https://open.maestrocollege.edu/question-the-numbers/percentages-and-percentage-points
publisher: Maestro College
---

# Percentages and percentage points

Lesson 2 of 16 in **Question the numbers** (DATA 101), unit "Numbers that summarize". An open lesson from Maestro College.

## What the learner will be able to do
- Calculate a percentage change from an old value and a new value.
- Explain the difference between a change in percent and a change in percentage points.
- Explain why a 50% drop followed by a 50% rise does not return to the starting value.
- Rewrite a misleading percentage claim so it is accurate.

## Teaching notes
Use cases like an interest rate moving from 2% to 3% (one percentage point, or a 50% increase). Have the learner check headline claims with small round numbers.

## 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 2 complete: Percentages and percentage points."
2. Give a two-line recap of what they learned.
3. Name the next lesson, "Rates, base rates and absolute versus relative change" (lesson 3 of 16), and give the learner its link: https://open.maestrocollege.edu/question-the-numbers/rates-base-rates-and-absolute-versus-relative-change.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: Averages, medians and outliers
Next lesson: Rates, base rates and absolute versus relative change