# Lesson 3

Which One?

These materials, when encountered before Algebra 1, Unit 1, Lesson 3 support success in that lesson.

### Lesson Narrative

The mathematical purpose of this lesson is for students to determine *when* to use each representation of data (box plots, dot plots, and histograms). Students should understand that each representation shows different features of the data set, and when to use each one is based on what type of information they are seeking about the data set. This lesson connects to previous work in grade 6, when students learned how to construct and interpret each representation. In the associated Algebra lesson, students collect data and create displays to represent the information they collect. The work in this lesson prepares students to compare and contrast data representations and discuss advantages and disadvantages of each data representation in a later lesson.

Students reason abstractly and quantiatively (MP2) as they understand data in context as well as in data displays and make connections among the representations. Students critique the reasoning of others (MP3) when they use data displays to assess the truth of statements given about a set of data.

### Learning Goals

Teacher Facing

- Determine which representation is appropriate to use in representing various data sets.

### Student Facing

- Let’s explore the best uses of box plots, dot plots and histograms.

### Required Materials

### Required Preparation

For one of the activities, you will need to collect the height in inches of each student. Consider setting up a way to accomplish this quickly. For example, affix one or more tape measures to the wall, so that students can simply stand in front of it while someone else observes their height. (Alternatively, you could just ask each student to tell you their height, making the tape measures optional.)