Curriculum  /  Math  /  7th Grade  /  Unit 5: Percent and Scaling  /  Lesson 2

Percent and Scaling

Lesson 2

Math

Unit 5

7th Grade

Lesson 2 of 19

Objective

Find percent of a number when given percent and the whole.

Common Core Standards

Core Standards

  • 7.RP.A.3 — Use proportional relationships to solve multistep ratio and percent problems. Examples: simple interest, tax, markups and markdowns, gratuities and commissions, fees, percent increase and decrease, percent error.
  • 7.NS.A.3 — Solve real-world and mathematical problems involving the four operations with rational numbers. Computations with rational numbers extend the rules for manipulating fractions to complex fractions.

Foundational Standards

  • 6.RP.A.3.C

Criteria for Success

  1. Identify values that represent part, percent, and whole in a percent situation. 
  2. Represent percent situations using visual diagrams such as tape diagrams or double number lines.
  3. Find a percent of a quantity using multiple strategies including tables, equations, and proportions.
  4. Solve percent problems efficiently. 

Tips for Teachers

  • The next three lessons, Lessons 2–4, are approaching 7.RP.3 and review solving percent problems finding part, percent, and whole. This lesson focuses on finding the part of a number when given the percent and the whole. Students recall strategies from sixth grade, such as tables, double number lines, and equations, while also using proportions, a new strategy learned in Unit 1 of seventh grade. These lessons may be combined or stretched as needed to meet the needs of your students. 
  • In order to provide opportunities for students to engage with standard 7.NS.3, calculators are not recommended to be used for every problem. In the interest of pacing, calculators may be used selectively. Students should use estimation and benchmark percentages to estimate answers and use as a check for reasonableness of the calculated answers (MP.5).
Fishtank Plus

Unlock features to optimize your prep time, plan engaging lessons, and monitor student progress.

Anchor Problems

25-30 minutes

Problem 1

In a school election, 60 students voted for the next student body president. Aliyah won 45% of the votes.

a.   Draw a visual representation of the problem. For example, you could draw a tape diagram or a double number line.

b.   Determine how many votes Aliyah won. Use any strategy, for example, creating a table, writing an equation, or setting up a proportion.

c.   Find a peer who used a different strategy to solve than you did. Compare and discuss your strategies and solutions.

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Problem 2

According to the U.S. Environmental Protection Agency, in 2013, people in the United States produced about 254 million tons of trash. Approximately 34.3% of this trash was recycled or composted.

About how many million tons of trash were recycled or composted in 2013? 

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

Student Response

Upgrade to Fishtank Plus to view Sample Response.

References

U.S. Environmental Protection Agency Municipal Solid Waste

Municipal Solid Waste is made available by the U.S. Environmental Protection Agency. Accessed Dec. 18, 2017, 6:21 p.m..

Problem 3

The chart below shows the number of students in each grade at a middle school.

Grade # of students
6th  94
7th 103
8th 93

Approximately 52% of students in the school participate in an after school activity. How many students participate in an after school activity?

Guiding Questions

Create a free account or sign in to access the Guiding Questions for this Anchor Problem.

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Problem Set

15-20 minutes

Give your students more opportunities to practice the skills in this lesson with a downloadable problem set aligned to the daily objective.

Target Task

5-10 minutes

Trevor received a $75 gift card to a local music shop for his birthday. After making a purchase at the shop, he has 16% left on the gift card. 

How much money is left on the gift card?

Student Response

Upgrade to Fishtank Plus to view Sample Response.

Additional Practice

The following resources include problems and activities aligned to the objective of the lesson that can be used for additional practice or to create your own problem set.

  • Include reasoning problems such as “Sam has 50% of a muffin and his brother Joe has 50% of a muffin. Sam has more muffin than Joe does. How is this possible?” or “Sam has 25% of a cookie and Joe has 50% of a cookie. Give a possible weight of each cookie if Sam has more cookie (in weight) than his brother does.”

Next

Find the whole given a part and percent.

Lesson 3
icon/arrow/right/large

Lesson Map

A7CB09C2-D12F-4F55-80DB-37298FF0A765

Topic A: Percent, Part, and Whole

Topic B: Percent Increase and Decrease

Topic C: Percent Applications

Topic D: Scale Drawings

Request a Demo

See all of the features of Fishtank in action and begin the conversation about adoption.

Learn more about Fishtank Learning School Adoption.

Contact Information

School Information

What courses are you interested in?

ELA

Math

Are you interested in onboarding professional learning for your teachers and instructional leaders?

Yes

No

Any other information you would like to provide about your school?

We Handle Materials So You Can Focus on Students

We Handle Materials So You Can Focus on Students

We've got you covered with rigorous, relevant, and adaptable math lesson plans for free