Unit 4, Lesson 11
Percentage Contexts
Grade 7
Preparation
Lesson Narrative
In this lesson, students are introduced to more applications of percent increase and decrease: interest, markups, discounts, and commissions. It is not necessary for students to memorize the meanings of these terms. The goal is for students to see that there are many different ways that percent increase and decrease are applied to money in the real world. In this lesson students practice finding:
- The new amount after the increase or decrease.
- The percentage that the increase or decrease is of the original amount.
As students make sense of what various percentages refer to in the context of a real-world situation, they reason abstractly and quantitatively (MP2).
- Comprehend “interest,” “markup,” “markdown,” and “commission” as other contexts that involve adding or subtracting a percentage of the initial amount.
- Determine the original dollar amount before a markup, markdown, or commission.
- Explain (orally) how to calculate the new dollar amount after a markup, markdown, or commission.
Let’s learn about more situations that involve percentages.
Required Preparation
It is recommended that students be provided access to four-function calculators so that they can focus on reasoning about how numbers are related to each other, representing those relationships, and deciding which operations are appropriate (rather than focusing on computation).