Unit 3, Lesson 2
Talking Percents
Extra Support Materials for Algebra 1
2.1
Warm-up
Standards Alignment
Building On
6.RP.A.3.c
Find a percent of a quantity as a rate per 100 (e.g., 30% of a quantity means 30/100 times the quantity); solve problems involving finding the whole, given a part and the percent.
Addressing
Building Toward
Materials
NoneActivity Narrative
This Math Talk focuses on finding the percentage of a number. It encourages students to think about parts of numbers and to rely on patterns to mentally solve problems. The understanding elicited here will be helpful later in the lesson when students will need to be able to find the percentage of a number.
To calculate the percentages, students need to look for and make use of structure (MP7).
Launch
Tell students to close their books or devices (or to keep them closed). Reveal one problem at a time. For each problem:
- Give students quiet think time, and ask them to give a signal when they have an answer and a strategy.
- Invite students to share their strategies, and record and display their responses for all to see.
- Before moving to the next problem, use the questions in the Activity Synthesis to involve more students in the conversation.
Keep all previous problems and work displayed throughout the talk.
Action and Expression: Internalize Executive Functions. To support working memory, provide students with sticky notes or mini whiteboards.
Supports accessibility for: Memory, Organization
Supports accessibility for: Memory, Organization
Activity
NoneEvaluate mentally.
- 50% of 200
- 25% of 200
- 6% of 200
- 3.2% of 200
Student Response
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Activity Synthesis
The goal of this discussion is to review students’ strategies for calculating percentages.
To involve more students in the conversation, consider asking:
- “Who can restate ’s reasoning in a different way?”
- “Did anyone have the same strategy but would explain it differently?”
- “Did anyone solve the problem in a different way?”
- “Does anyone want to add on to ’s strategy?”
- “Do you agree or disagree? Why?
- “What connections to previous problems do you see?”
MLR8 Discussion Supports. Display sentence frames to support students when they explain their strategy. Examples:
Advances: Speaking, Representing
- “First, I because .”
- “I noticed , so I .”
Advances: Speaking, Representing
2.2
Activity
Instructional Routines
NoneMaterials
NoneActivity Narrative
The purpose of this activity is for students to practice calculating percentages of shapes that share a specific characteristic. In doing so, students consider the exact categories needed to calculate a percentage. Students must determine which rate is the appropriate one to represent as a percent based on the question. As students calculate multiple percentages from the data set, they have the opportunity to look for and express regularity in repeated reasoning (MP8). Monitor for students who create two-way tables to organize the shapes.
Launch
Allow students to work in pairs. Provide students with an example of how completed statements should look.
Example: 4 of the 24 shapes are gray. 17% of the shapes are gray.
Activity
None2.3
Activity
Materials
NoneActivity Narrative
The purpose of this activity is for students to practice calculating percentages from data, similar to what they encounter in the associated Algebra 1 lesson. In the previous activity, students practiced thinking about specific categories within groups before calculating a percentage. Here, students extend this thinking by applying it to data that are collected from their classmates.
When students articulate their reasoning, they have an opportunity to attend to precision in the language they use to describe their thinking (MP6). They might first propose less formal or imprecise language, and after sharing with a partner, revise their explanation to be clearer and stronger.
This activity uses the Stronger and Clearer Each Time math language routine to advance writing, speaking, and listening as students refine mathematical language and ideas.