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XY Encounter Funded by the
US Department of Education

Teacher's Guide: Part 1: Introduction - "Right here in our city!"

Watch Video Clips @ XY Encounter Streaming Video Page

Map of
Teacher's
Guide
Part 1 Part 2 Part 3 Part 4

Introduction Introduction Introduction Introduction

Pause Point 1 Pause Point 1 Pause Point 1 Pause Point 1

Pause Point 2 Conclusion Pause Point 2 Conclusion

Pause Point 3 Conclusion

Conclusion

Setting:

Max & Keisha stop by his room to check his email. Max thinks he has accidentally keyed into a secret government Web site that indicates extraterrestrial life has been sighted beneath New York City. It doesn’t occur to him that he’s easily able to access the Web site using his own password. Max and Keisha print out two tables of values, which they use to plot the points and make a graph on a coordinate grid to help locate the alien. When values on both tables are graphed, Max and Keisha see that if extended, one graph intersects the other – and the point where they intersect is the location where they’ll find the alien.

Standards:

Organize data using tables and graphs.

Represent and investigate how a change in one variable relates to a change in a second one.

Represent and record patterns using tools such as tables and graphs.

Create a coordinate graph, which includes an understanding of axes, origin and scale, and locate points by naming ordered pairs.

Objectives:

Complete a table of values and plot points, as well as construct a graph on a coordinate grid.

Construct two graphs on the same coordinate system, and identify the point of intersection.

Materials:

Prepare student copies of the activity sheet, “Right Here in Our City,” (.pdf format) and an overhead transparency, if desired.
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Mathematically Speaking:

This exercise is unique because students rarely have opportunities to solve problems involving the plotting of two lines that intersect on a coordinate system.

Students may need experience with the plotting of ordered pairs by moving horizontally along the x-axis first before moving vertically along the y-axis. Students often reverse the ordered pair and think that (3,2) is the same as (2,3). Point out that these sets of ordered pairs identify two different points.

Background information:

When Max discovers the secret Web site, Keisha points out that the URL is followed by “.gov.”

Student use of the “sweep” or highlight function of the computer will vary according to the software used. On the video, Max was able to operate the mouse to sweep the data, which the computer simultaneously plotted on the grid.

Although the secret Web site in the video is fictitious, the information about a “golden disk” is authentic information from NASA. In 1977, the U.S. launched two unmanned space probes, Voyager 1 & Voyager 2. Each carried a gold-plated record that contained math symbols, songs, pictures, sounds from earth, and a map of the earth’s location so that other beings would be able to interpret the information, if found.

Vocabulary:

The XY Encounter, Part 1 lays the groundwork for introducing:

  coordinate grid
  ordered pairs
      or coordinates
  quadrant
  superimposed
  extend
  x-axis
  y-axis
  origin
  location
  point(s)
  scale
  map
  orientation
  intersection