Money Math · Lesson Plan

Percent of Increase

Prices change over time, and a percent of increase describes how much a price has gone up. This lesson teaches the method: find the difference between the new and original price, write it as a ratio over the original amount, and convert that ratio to a percent — using either a proportion out of 100 or division. Students then practice on ten price-change scenarios.

Grades 6–9 Lesson Plan 30–45 minutes Free Lesson Plan Lesson & Worksheet: Full Membership

For Teachers

Lesson at a glance

Topic: Money Math
Grade Level: Grades 6–9
Resource Type: Lesson + Worksheet
Estimated Time: 30–45 minutes
Format: Lesson + worksheet + answer key
Materials: Printable lesson, worksheet, answer key, calculator

What Students Learn

Learning objectives

Define percent of increase
Find the difference between an original and a new price
Write the increase as a ratio over the original amount
Convert a ratio to a percent using a proportion or division
Solve percent-of-increase problems with money amounts

Materials

What you’ll need

Printed copies of the lesson and worksheet (one per student)
Calculators
Pencils
Whiteboard or projector for worked examples

Key Terms

Vocabulary

Percent of increase: The percent by which a price or amount has gone up over time.
Original amount: The starting price before the change.
New amount: The current price after the change.
Difference: The result of subtracting the original price from the new price.
Ratio: A comparison of two numbers, often written as a fraction.
Proportion: An equation stating that two ratios are equal.

For Teachers

Lesson plan

Estimated time: one 30–45 minute class period.

Lesson sequence

Introduction (5 min). Use the amusement-park ticket example ($25 → $35): by what percent did the price go up?
Teach the method (12 min). Find the difference, write it over the original amount, then convert the ratio to a percent two ways — a proportion out of 100 and dividing the numerator by the denominator.
Worksheet (15 min). Students find the percent of increase for ten original/new price pairs.
Review (8 min). Check answers with the answer key and discuss where prices rise in real life.

Assessment

Assess the completed worksheet against the included answer key.

Discussion

Discussion questions

What does a percent of increase tell you about a price?
Why do you compare the difference to the original amount, not the new amount?
What are two ways to convert a ratio to a percent?
Where in everyday life do you see prices increase by a percent?
If two items rise by the same dollar amount, will they have the same percent of increase? Why or why not?

Printable Lesson, Worksheet & Answer Key