Overview

Using graphing calculator technology, students learn about creating and interpreting graphs. This lesson is to be used as an introduction to interpretation of graphs.

Objective

Students will be able to describe an appropriate scenario given a graph or choose an appropriate graph given a scenario.

Standards Addressed

Mathematics — Data Analysis

Grade 4

Data Collection, Benchmark B

02. Represent and interpret data using tables, bar graphs, line plots and line graphs.

05. Propose and explain interpretations and predictions based on data displayed in tables, charts and graphs.

 

Grade 5

Data Collection, Benchmark C

05. Modify initial conclusions, propose and justify new interpretations and predictions as additional data are collected.

 

Grade 8

Statistical Methods, Benchmark F

06. Make conjectures about possible relationship in a scatter plot and approximate line of best fit.

09. Construct convincing arguments based on analysis of data and interpretation of graphs.

Materials

• Overhead projector

• TI-83 or TI-84 view screen

• TI- 83 or TI-84 calculator

• CBR with cords, screen or blank wall to project on

Vocabulary

• Coordinate plane (quadrant one)

• X-coordinate, y-coordinate

• X-axis (time)

• Y-axis (distance)

• Origin

• Independent variable

• Dependent variable

Procedure

1. Control the calculator for younger groups. Have older students do the projects themselves. (Directions for the calculator are included as a separate sheet)

2. Group students in teams of four or five.

3. Introduce students to the CBR (students are told that they will be working with a device with a magic eye).

4. Ask for a volunteer to walk down a hallway. Let students look at the graph created. Allow for another volunteer.

5. Students should discuss in their groups what they think is being measured.

   What two variables are involved in the graph? Answer: Distance in feet and time in seconds.

   What is happening at the origin? Answer: No time has elapsed and no distance was traveled.

6. Discuss answers. Decide appropriate labels to figure out speed — -ft./sec. or mi./hr. or in./min.? (An extension of the lesson could address an additional variable discussion of conversion between units.)

7. Describe situations and ask students to model them by walking and checking their path on the calculator, if possible, i.e. line straight across (zero slope), downhill (negative slope), uphill positive slope, vertical line (undefined).

8. Show a match graph and ask groups to discuss how they think they should walk to re-create the graph. Have groups write down their plan. Call on students to walk and attempt to match it. Discuss the graph created, revise the plan and try again. Do several times with students from various groups.

9. Discuss distance from origin at start of graph, speed (rate of change of the graph), slope of the line and what is occurring when slope is positive or negative. (For younger groups you may want to omit discussion of slope.)

10. Show a match graph and devise a possible scenario to go with it (e. g., Bob left his house to walk to his friend’s house. Halfway there he stopped to talk with the postman, looked and saw that he was late and ran the rest of the way there.) Have a student act out your scenario and see if it matches the graph.

11. Give students another graph and ask them to come up with a possible scenario in their groups. Have various groups give their scenarios and then act them out to see if they match the graph correctly.

12. Give students several scenarios and ask them to draw an appropriate graph in their groups. The correctness can be checked by acting it out and having the graph drawn.

13. Give students “exit tickets” to be completed individually to check comprehension.

Evaluation

Use Interpreting Graphs Direction Sheet and Exit Ticket student handouts.