## Classroom Video: Modeling - Section 3: Box Plots

# Introduction to Box Plots

Lesson 14 of 22

## Objective: SWBAT: • Identify and label the minimum, maximum, lower quartile, upper quartile, and mean of a data set and box plot. • Analyze and compare box plots.

#### Do Now

*7 min*

See my **Do Now** in my Strategy folder that explains my beginning of class routines.

Often, I create do nows that have problems that connect to the task that students will be working on that day. Today I want students to analyze a circle graph in order to answer questions. Each edition of Scholastic Action typically includes a graph on its back page.

I ask for students to share their thinking. Students are engaging in **MP3: Construct viable arguments and critique the reasoning of others**.

*expand content*

#### Problem

*7 min*

I introduce the problem to students. I want students to apply what they already know minimum, maximum, and median to analyze the box plot. Students participate in a **Think Write Pair Share. ** I walk around and monitor student progress as they work.

I call on students to share out their ideas. I push students to support their idea with data from the set. I am interested to see what students think about the dots at 28 and 39. Students are engaged in **MP3: Construct viable arguments and critique the reasoning of others **and** MP2: Reason abstractly and quantitatively**.

*expand content*

#### Box Plots

*6 min*

I reveal the name and definition of each part of the box plot. I show students that finding the lower quartile and upper quartile is just finding the median of a different part of the data set. I want students to see the connection between how each part is identified in the data set and then translated to the box plot.

*expand content*

#### Percent of Data

*7 min*

I have students participate in a **Think Write Pair Share**. Students are engaging in **MP3: Construct viable arguments and critique the reasoning of others.** I want students to make a connection between what they know about the median and the percent of data. If students understand that a median splits the data set down the middle, they should understand that 50% of the data is before the median and 50% of the data is after the median. Students can use the same reasoning to determine that 25% of the data is between the minimum and the lower quartile.

I call on students to share out their observations. If students are struggling, I may ask one or more of the following questions:

- How fraction of the data is before the median? After?
- How can we express that as a percent?
- What does the upper quartile represent?
- What percent must be after the upper quartile?

I want students to share out what they think the word quartile means. If students are struggling, I write these words on the board: quart, quarter, and quartet. I ask students to think about what the word part “quart” means in each word. I want students to see that *quart- *connects to four. There are four quarts in a gallon, four quarters in a dollar, and four people in a quartet. If we break our data into *quartiles*, we are breaking it up into four parts. This means that each quartile represents ¼ or 25% of the data in the data set.

*expand content*

#### Analyzing Box Plots

*13 min*

**Note:**

- Before this lesson I create and
**Post a Key.**

I explain to students that they will be working to analyze the box plots. I ask students what they can do if they get stuck. I want students to realize that they can check their notes and check in with their partner if they are stuck, before asking me a question.

As students work, I walk around and monitor student progress and behavior. If students complete a page, I quickly scan their work. If they are on track, I send them to check their work with the key. If students are struggling, I may ask them one of the following questions:

- What is the question asking?
- What is does this part of the box plot tell us? Where can we find it?
- What did our notes say?
- What does a quartile represent?

If students complete the questions they can work on the challenge problems.

*expand content*

#### Closure and Ticket to Go

*10 min*

I ask students to flip to the closure problem. I ask students how the age of the players on the Houston Rockets compares to the age of the players on the Chicago Bulls. I explain that they need to write 5 observations by analyzing the box plots. They can use the questions at the bottom to help them if they are stuck.

Students participate in a **Think Pair Share. **Students are engaging in **MP1: Make sense of problems and persevere in solving them **and** MP3: Construct a viable argument and critique the reasoning of others**.

I call on students to share out their observations. I push students to use accurate language and to use the box plot to support their observation. Students are engaging in **MP6: Attend to precision**.

I pass out the **Ticket to Go **and the **Homework.**

*expand content*

*Responding to Morgan Hardy*

Thanks, Morgan! Â I'm glad I could help!

| one year ago | Reply

Just used this lesson today.Â I really liked how the lesson emphasized that each quartile contains 25% of the data.

| 2 years ago | Reply

- UNIT 1: Intro to 6th Grade Math & Number Characteristics
- UNIT 2: The College Project - Working with Decimals
- UNIT 3: Integers and Rational Numbers
- UNIT 4: Fraction Operations
- UNIT 5: Proportional Reasoning: Ratios and Rates
- UNIT 6: Expressions, Equations, & Inequalities
- UNIT 7: Geometry
- UNIT 8: Geometry
- UNIT 9: Statistics
- UNIT 10: Review Unit

- LESSON 1: 100 Students Project: What If The World Were 100 People?
- LESSON 2: 100 Students Project: What do we want to know about our students?
- LESSON 3: 100 Students Project: Revising Questions & Planning the Survey
- LESSON 4: 100 Students Project: Conducting the Survey
- LESSON 5: 100 Students Project: Tallying Data and Brainstorming about Presentations
- LESSON 6: 100 Students Project: Analyzing Survey Results
- LESSON 7: 100 Students Project: Presenting Your Findings
- LESSON 8: 100 Students Project: Project Reflection
- LESSON 9: Median, Mode, and Range
- LESSON 10: Mean
- LESSON 11: Playing with Measures of Central Tendency
- LESSON 12: Choosing the Best Measure of Center
- LESSON 13: Show what you know
- LESSON 14: Introduction to Box Plots
- LESSON 15: Box Plots and Interquartile Range
- LESSON 16: Arm Span Day 1
- LESSON 17: Arm Span Day 2
- LESSON 18: Mean Absolute Deviation
- LESSON 19: Comparing Mean Absolute Deviation
- LESSON 20: Selecting Measures of Center and Variability
- LESSON 21: Statistics Jeopardy
- LESSON 22: Unit Test