Lesson 8 More Questions about Scaled Bar Graphs

    • Let’s solve problems using data shown on bar graphs.

Warm-up Number Talk: Repeated Addition

Find the value of each expression mentally.

Activity 1 New School Year

A group of students were asked, “How are you feeling about the new school year?” Their responses are shown in this bar graph:

Bar graph. Feelings About the New School Year. Vertical axis labeled number of students from 0 to 60 by 5s. Horizontal axis labeled feelings: excited, nervous, curious. Height of bar: excited, 55. nervous, 23. curious, 25.

How many more students are excited about the new school year than are nervous or curious?

Activity 2 Use Bar Graphs to Solve Problems

The bar graph shows how many of each type of tree Clare saw on the way home. Use the graph to answer the questions. Show your thinking using expressions or equations.

Bar graph. Trees I saw on the way home. Horizontal axis labeled oak, pine, maple, fir. Vertical axis from 0 to 100 by 10s. Height of bar: oak, 29, pine, 82, maple, 15, fir, 58.

  1. How many more pine trees did Clare see than fir trees?

  2. How many more pine trees did Clare see than oak or maple trees?

  3. How many fewer oak trees did Clare see than pine trees?

  4. How many fewer maple or oak trees did Clare see than fir trees?

Practice Problem

Problem 1

The scaled bar graph shows how many students are in each class.

Bar graph. Students in Each Class. Vertical axis labeled number of students from 0 to 35 by fives. Horizontal axis labeled class 1, class 2, class 3, class 4. Height of bar: class 1, 24. class 2, 25. class 3, 22. class 4, 31.

  1. How many students are in the 4 classes altogether? Explain or show your reasoning.

  2. How many fewer students are in class 1 than in class 4? Explain or show your reasoning.