Jamie Preston
Mayor's Commission on Literacy
Expert Trainer Assignment #5
December 12, 1997

Using Internet Lemonade Stand to Teach Probability

Grade level

Grade 3 literacy level to GED

Objectives

1) Demonstrate that probability predicts whether an outcome is more or less likely, but it is not a "sure thing."

2) Work with decimal values.

3) Reinforce skills in note-taking and following directions.

Materials

1) A set of seven pennies for each student or group.

2) Access to the World Wide Web. (If there are not enough online work stations, students may work in pairs or small groups.)

3) Students are expected to have notebooks and pens or pencils.

Procedures

1) If there are wide ability ranges (in terms of literacy levels or computer competence), group low-level students with high-level students.

2) Explain that probability is useful in making educated guesses, but it offers no guarantees.

3) Ask the student(s) what it means to__¹ have a 50-50 chance of winning. (Winning and losing is equally possible.) How about a 75-25 chance of winning? (Winning is three times as likely as losing.)

4) Distribute seven pennies to each student or group. Ask the student(s) to toss each coin and use notebooks to record whether it was heads or tails for each.

5) Ask the student(s) to explain why there were more heads or tails.

6) Ask the student(s) to call up Lemonade Stand by going to a screen that has a window for a URL and typing in www.littlejason.com/lemonade/ and Enter (or Return).

7) Click here to go over the rules. The directions should be read aloud by the instructor or a student, depending on student readiness. The student(s) should say what each rule means. Explain the difference between revenues and profits.

8) Click on Click here to return to the main page.

9) Click on Start the game.

10) Ask each student or group to type in a nickname_D, then click on the "Register Me!" box.

11) For each of the 25 days, the student(s) should record the predicted chance of rain and whether is was actually sunny or rainy, and they should note their final scores and their profits.

12) Coach students in playing the game, keeping in mind the objectives of the lesson.

Evaluation

1) Was each student or group able to understand directions, probability, and decimals well enough to complete the game? (If not, analyze the problem and provide additional instruction before inviting a second attempt at Lemonade Stand.)

2) Write_® the following sentence on the board or give photocopies to each student:

An 80% chance of rain means it will definitely rain. (True or False)

If there are differences of opinion, ask each side to explain its reasoning.

3) Ask the student(s) to report how many times during the 25 days it rained wasn't supposed to and it was sunny when rain was more likely.

4) Repeat Step 2, if needed.

5) For a class: Based on the final scores for the first game, which student (or group), do they think will win a second game? Play again and see how the predictions match the outcomes.

For an individual: Play again and use what you've learned about probabilities to make a higher score.