Type or download the POINTS and PTGAME programs into your calculator and become familiar with each of them. Install the programs into the student calculators prior to teaching this lesson.
To download these programs to your calculator:
- Right click on the links above and choose Save Target As....
- Save the file to your computer, in a location that you will easily remember.
- Connect your calculator to your computer with a TI Graph LinkTM cable, and turn your calculator on.
- Go to the location where you saved the file, right click on the filename or icon for the program, and choose Send to TI Device...
- The file transfer should begin. (If it does not, you may need to download the TI Graph-LinkTM software from the Texas Instruments web site. Enter "Graph Link" in the Search box, and then find the correct software for your computer and calculator.)
- Once downloaded, you can access the programs by pressing the PRGM button and selecting the program you wish to run.
Alternatively, students can enter the programs into their calculators, using the code from the Program Code sheet.
Look through the Line ‘Em Up activity sheet. Complete the activity sheet in advance, to familiarize yourself with the questions.
The class should be divided into teams of three or four students. Each student should have a graphing calculator containing the POINTS and PTGAME programs and a copy of the Line ‘Em Up activity sheet. (Note that the activity sheet contains three parts. The first page is a description of the problem and a brief overview of the terms associated with the coordinate plane. The second through fifth pages contain a series of questions and activities for students to complete that will teach them about plotting points. The last two pages contain questions specifically about the Line ‘Em Up game. At this point, you may wish to distribute only the first part to students. After providing an overview of the coordinate plane, you can distribute the second part. And, you might want to wait to distribute the third part until after you have played the Line ‘Em Up game with students.)
Read the problem aloud to your students. Ask a student to describe the problem in her own words. Emphasize that the purpose of the activity is to explain to Lisa how two numbers can determine the location of a point.
In general terms, discuss the coordinate plane, including the location of the x-axis, y-axis, Quadrant I, Quadrant II, Quadrant III and Quadrant IV. Explain that that the x-axis and y-axis do not always have to intersect at, or even near, the center of the coordinate plane and, sometimes, only one or two quadrants may be visible. Finally, discuss that each position on the coordinate plane can be identified by an ordered pair: the first number is the x-coordinate, and the second number is the y‑coordinate. Do not go any further than this with the discussion. This should be an overview only. Allow students to discover how to plot points on their own, by answering Questions 1‑9 on the activity sheet.
Ask your students to turn on their calculators. If you have a calculator view screen and an overhead graphing calculator, this would be the perfect time to use it. Walk students through the steps of running the POINTS program. The process for using the program is fully described on the second page of the activity sheet. Pause at the end of each step, and circulate among students to make sure that everyone is at the same point. Have team members help those who are having difficulties.
Explain to students that they will always want to enter "1" when asked, "Plot More Points?" That way, the calculator is ready to receive the next input values for the x-coordinate. They should only enter "0" when they are finished with the worksheet and want to exit the program.
When you are satisfied that everyone understands how to use the program, allow the students to complete the worksheet. Remind students that this is a group activity and you should discuss your observations.
While the students are working and discussing their observations with team members, circulate around the classroom. Listen to the group’s conversation and intervene when it seem as if they are going in the wrong direction. Randomly ask different teams to explain how they arrived at their responses, especially to Questions 2, 4, 6 and 7. If you are not satisfied with their response, ask probing questions, such as, "How does the location of the point (2, 1) change if the first number is changed to ‑2?" Continue to question until you feel that they are making a connection. Visit each group at least once.
When all teams have answered Questions 1‑9, have a whole class discussion. Raise such questions as:
- How did you fill in the blanks in Question 7?
- Where would a point be located if both coordinates are positive? …both negative? …one of each?
- What would you write in your letter to Lisa explaining how two numbers determine the location of a point?
Following the discussion, play Line ‘Em Up with the class. Distribute the Game Boards and chips to students. (Regular size bingo chips are too large to represent points on the coordinate plane. Therefore, you may want to create your own chips by punching holes in heavy cardstock; the removed circles work great. Dry lentils also work well.) In a small bag or box, place the Ordered Pair Cards. Randomly select one ordered pair at a time, and read the point aloud to students. Students should mark that point on their game board. If a student gets six points in a straight line, she should yell, "Line Up!" The six points should then be verified to ensure that the student did not make a mistake.
If you have not already done so, distribute the last two pages of the activity sheet after playing the game. Allow students to complete these two pages, either with the remaining time left in class or as a homework assignment.
