Comparing Groups; Activity 2: More Team Heights (IM Grade 7, Unit 8, Lesson 11)
Task
Lesson Purpose In this lesson, students review measures of center and variability from grade 6. They also work to informally decide whether or not two distributions are very different from each other (MP3). This lesson introduces the idea of expressing the difference between the centers of two distributions as a multiple of a measure of variability as a way to help students make this determination (MP2). How Tuva Enhances the lesson Tuva supports this lesson by making the structure of the data and comparisons more visible, allowing students to focus on reasoning about distributions rather than managing representations. In this lesson, students compare groups using dot plots and measures of center and variability. Tuva allows all four teams to be displayed accurately and simultaneously, giving students consistent access to the full data set throughout the lesson. This makes it easier for students to notice similarities, differences, and overlap across groups without needing to recreate or reinterpret multiple graphs. Tuva’s dynamic dot plots ensure that each distribution is represented correctly. This reduces the chance that small errors in hand-drawn graphs interfere with comparisons and conclusions, helping students base their arguments on the data itself. Built-in tools for calculating and displaying the mean, median, and mean absolute deviation allow students to connect numerical measures directly to the visual distribution. Seeing these measures alongside the dot plots supports deeper understanding of center and variability and reinforces the idea that both are needed to compare groups meaningfully. By lowering the representational load, Tuva helps students stay focused on the lesson’s mathematical goals: interpreting distributions, justifying comparisons, and deciding when groups are meaningfully different.
Comparing Groups with Dot Plots Have you ever noticed that players on some sports teams seem taller than players on other teams? Sometimes people even guess what sport someone plays based on their height. In this lesson, you’ll look at height data from different sports teams and use graphs and numbers to compare groups. Instead of just saying one team is “taller,” you’ll figure out how much taller—and decide what counts as a meaningful difference. In this lesson, you will use dot plots and numerical measures to compare the heights of different groups of people. You’ll explore: How groups are similar or different How much taller one group might be than another Whether two groups are clearly different or have a lot of overlap Learning Goal Let’s compare two groups using dot plots and numbers. Click Next to Get Started!
Topics and standards: 7-SP-B-3, Grade 7, Illustrative Math & Tuva, 7.SP.B