Ratios and Proportions: Percents of Change

Objectives:

• Students will review the basics of percentages.

• Students will learn how to calculate the % of a decrease.

• Students will learn how to calculate the % of an increase.

• Students will practice find % of increases and decreases.

Suggested Grades:

Sixth Grade - Seventh Grade - Eighth Grade - Ninth Grade - including special education students

Lesson Procedure:

Print the classroom lesson plan and worksheet questions (see below).

Lesson Excerpt:

II. Percents of Change

- "Today we are going to be looking for more percentages. Only today's percentages are what you look for when something changes. Usually an amount or a quantity changes over time. Last year, you might have made $6.00 an hour babysitting and this year you might be making $8.00 an hour. You have had a change in the amount of money that you have made. This is called "Percents of Change."
- "Percents of Change is a fancy way of saying that there has been a change in an amount of quantity over time. It might be an increase as in the babysitting example, or it might be a decrease. When we are looking for a percent of change, we want to find what the percent of the increase or decrease was. That is what we are going to be looking for in today's lesson."
- "Let's write the example that I just talked about on the board."

Continued...