### Lesson Summary

### Overview

Students watch a set of *Cyberchase* video clips which show that between two points there is exactly one line, and that if two lines intersect, they intersect at a point. These ideas are used to motivate students to learn to plot points in all four quadrants, draw line segments connecting pairs of points, and find the coordinates of the intersection.

### Grade Level:

5-8

### Suggested Time

1 hour

### Media Resources

Two Points Determine a Line QuickTime Video

Two Sightings, Different Information QuickTime Video

Finding the Intersection QuickTime Video

### Materials

Handout 1: Using Coordinate Graphing to Find Point Locations in All Four Quadrants

Handout 2: Graphing in a Coordinate Plane

Assessment: Level A

Assessment: Level B

Answer Key

### The Lesson

### Part I: Learning Activity

1. Students work in pairs for this activity.

2. Read the following to your students: "In this episode, Digit loses the Critical Network Interface Card (NIC), which allows Hacker to use the Transformatron to take over Cyberspace. The CyberSquad must the find the Transformatron in order to retrieve the NIC from Hacker, and save Motherboard. They use maps to locate places where the NIC is located. You will watch three video clips that identify several important properties of points and lines, and then you will use the coordinate plane to solve similar problems."

3. Tell the students that in the first video clip, Digit discovers an important property of two points on a plane. Ask students to figure out what this property is as they watch the video clip.

4. Play the Two Points Determine a Line QuickTime Video .

5. Briefly discuss with the students how two points determine a line, and whether they could draw more than one line through a given pair of points. Ask the students whether it surprised them that there is only one line formed by two points.

6. Tell the students that in video clip 2, Matt and Jackie cannot figure out why they can both see the Transformatron even though they are in different locations. Digit and Inez identify one possible property of two lines on a plane. Ask students to watch to determine what this property is.

7. Play the Two Sightings, Different Information QuickTime Video .

8. Briefly discuss with the students what Digit and Inez have diagrammed, and why this diagram poses a problem for Matt and Jackie's goal to locate the transformatron.

9. Tell the students that in the third video clip, Inez and Digit figure out their mistake from video clip 2. Ask students to look for this mistake as they watch the video clip.

10. Play the Finding the Intersection QuickTime Video .

11. Ask the students what property of two intersecting lines helps Digit and Inez identify the location of the transformatron.

12. Distribute Handout 1: Using Coordinate Graphing to Find Point Locations in All Four Quadrants .

13. Ask the students to complete the handout. For some students, learning to plot points can take considerable practice. Handout 2: Graphing in a Coordinate Plane can be used to review plotting points on a coordinate plane.

14. Discuss student answers from the handouts.

### Part II: Assessment

Assessment: Level A (proficiency): Students are asked to plot points for given pairs of coordinates, and to determine the coordinates of points graphed in the coordinate plane.

Assessment: Level A (above proficiency): Students apply their knowledge from the Cyberchase video clip to graph points on the coordinate plane, connect pairs of points with carefully-drawn line segments, and determine whether three resulting line segments will intersect in a single point.