Posing Percentage Problems

10 min

Teacher Prep
Setup
Groups of 3--4. Provide a set of newspaper clippings involving percentage increase and decrease for each group.

Narrative

In this group activity, students take turns sorting news clippings based on whether they involve percentage increase or decrease. This prepares students for a future activity when they will analyze some of these situations more closely.

As students trade roles explaining their thinking and listening, they have opportunities to explain their reasoning and critique the reasoning of others (MP3).

Launch

Arrange students in groups of 3–4. Provide each group with a set of newspaper clippings. Tell students that they will take turns sorting the clippings according to whether they represent a percent increase or a percent decrease and that they should explain their reasoning. If time allows, demonstrate the steps with a student as a partner. Consider demonstrating productive ways to agree or disagree, for example, by explaining mathematical thinking or asking clarifying questions.

MLR8 Discussion Supports. Students should take turns finding a match and explaining their reasoning to their partner. Display the following sentence frame for all to see: “I noticed ​_ , so I matched . . . .” When students disagree, encourage them to challenge each other using these sentence frames: “I agree because . . . .” and “I disagree because . . . .” This will help students clarify their reasoning about which quantity corresponds to 100%.
Advances: Conversing, Representing
Representation: Access for Perception. Ask students to read the news clippings aloud to their partners. Students who both listen to and read the information will benefit from extra processing time.
Supports accessibility for: Language, Attention

Student Task

Your teacher will give you a variety of news clippings that include percentages.

  1. Take turns with your partner to sort the clippings into two piles: those that are about increases and those that are about decreases.

    1. For each clipping that you sort, explain to your partner how you decided which pile to sort it into.

    2. For each clipping that your partner sorts, listen carefully to their explanation. If you disagree, discuss your thinking and work to reach an agreement.

  2. Were there any clippings that you had trouble deciding which pile they should go in?

Sample Response

  1. No written response required.
  2. Answers vary.
Activity Synthesis (Teacher Notes)

Much discussion takes place between partners. Invite students to share how they decided the category for any clippings that were difficult to sort.

  • “What were some ways you handled . . . ?”
  • “Describe any difficulties you experienced and how you resolved them.”

If time permits, invite students to discuss any interesting contexts from the clippings.

Standards
Addressing
  • 7.RP.3·Use proportional relationships to solve multistep ratio and percent problems.
  • 7.RP.A.3·Use proportional relationships to solve multistep ratio and percent problems. <span>Examples: simple interest, tax, markups and markdowns, gratuities and commissions, fees, percent increase and decrease, percent error.</span>

10 min

20 min