Illuminations: Information Represented Graphically

Information Represented Graphically

Name Your Tune

The activities in this lesson focuses on studying information displayed in pictographs that report the sales of records, tapes, and compact discs for one week at a music store. The students are asked to discuss and then describe the information and to explain the numbers sold in each category. They are asked to defend their explanation.

Learning Objectives
 
Students will:
  • describe and explain information displayed in pictographs
  • make written predictions from the information

Materials
 
Name Your Tune Activity Sheet

Instructional Plan

Prior to distributing the activity sheet, ask students to list different types of graphs they might use to represent data. Students may suggest any of the following:

  • bar graph
  • line graph
  • circle graph
  • pictograph

 

Guide the discussion to pictographs as a means of displaying data. Ask students questions such as:

  • How is data represented in a pictograph?
  • What does each picture or symbol stand for?
  • How are pictographs useful for looking at data?

 

Distribute the Name Your Tune activity sheet to each student.

Name Your Tune Activity Sheet Name Your Tune Activity Sheet

Individually, students should read the title of the graph and interpret the information at the bottom. In groups of three, students should give their interpretation of the information in the graph and each of its sections.

In their groups, ask the students to explain:

  • why the store might want to know this information for different types of music rather than the sales as a whole;
  • what might happen if they looked at the store-wide sales for the various formats rather than the separate types of music.

 

Have the students read the information for the different types of music and formats. The students should write the number of sales next to each graph.

Still in their groups, students should read and discuss questions 1 through 6. In their discussion, have the students tell why they think:

  • the total sales vary for the different types of music.  What do the differences imply about the interests of clients, the location of the store, prices, and so on?
  • the total sales vary for the different formats;
  • the sales vary for the various formats according to the different types of music.

 

Allow enough time in the discussion for every student in the group to offer a suggestion.

Individually, students should complete questions 7 and 8. Ask the students to share their explanations with a fellow classmate.

 

 

Possible Solutions for the Activity Sheet

Question 1. All of the graphs use a "note" symbol to represent ten units sold. Each graph shows the types of music and recordings sold. Graphs are different because the number of units sold varies.

Question 2. Tapes are less popular than records or CDs.

Question 3. Rock tape sales and country-music tape sales were equal (10 tapes were sold for each kind of music.)

Question 4. 120 CDs were sold in all.

Question 5. Overall, records are most popular. 220 records were sold, whereas only 120 CDs, and 40 tapes were sold. (However, in the classical music category, CDs were the most popular.)

Question 6. Rock is the most popular type of music, because 120 units of rock were sold.

Question 7. Student questions may vary.

Question 8. People have different types of equipment (record players, tape players, and CD players) on which they play their music selections.

Extensions
 
  1. In pairs, have the students evaluate the use of a picture graph to show the sales at the music store. The students should write what type of graph (bar, scatter plot, picture, or circle) they think is the best for showing the information and why that graph is better than any other type.

  2. Have the students work together to plan the music store's future purchases. Tell the students the store plans to order 5000 units. The students can work in small groups to decide the number that should be ordered for each type of music and each format.

NCTM Standards and Expectations
 
Data Analysis & Probability 3-5
  1. Represent data using tables and graphs such as line plots, bar graphs, and line graphs.
  2. Propose and justify conclusions and predictions that are based on data and design studies to further investigate the conclusions or predictions.

References
 

  • Irons, Calvin and Irons, Rosemary.  The Arithmetic Teacher. October, 1991. vol. 39, no. 2.  p 26 - 33.

  
1 period   

NCTM Resources

Principles and Standards for School Mathematics
National Council of Teachers of Mathematics Thinkfinity Verizon Foundation
More and Better Mathematics for All Students
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