Rock Paper Scissors

Probability: The Study of Chance Subject(s): * Mathematics/Probability Context: The theory of probability is an important branch of mathematics with many practical applications in the physical, medical, biological, and social sciences. An understanding of this theory is essential to understand weather reports, medical findings, political doings and the state lotteries. Students have many misconceptions about probability situations. Goals: The student will learn the basic principles of probability. OBJECTIVES: The student will: 1. Diagram possible outcomes using a tree diagram. 2. State the rule (definition) for probability.

Motivation/Set Procedures: 1. Hold up a Tennessee Lottery ticket. 2. Ask for guesses as to the odds of winning. 3. Give another example of a pick three lottery. 4. Have a volunteer pick 3 numbers. 5. Ask for guesses. 6. Reveal answer. (1-1,000) 7. Reveal answer to Powerball lottery (1-146,107,962). 8. Ask “Why are these numbers so big? 9. Ask “Do you think buying a lottery ticket is a good idea? Why? 10. Ask “What are some other ways probability is used?

Question: How do you calculate probability? Next Step: We will conduct an experiment and discuss probabilities and the methods used to calculate them. RESOURCES AND MATERIALS: * Activity sheet * Pencils * Paper PROCEDURES: 1. Introduce activity with a demonstration of game: “Rock, Paper, Scissors.” 2. Divide class into pairs (player A and player B) and have them play the game 18 times and keep a tally on activity sheet. 3. Have each pair share their scores and record on board. 4. Discuss results. 5. Do a tree diagram to determine the possible outcomes. 6. Answer the following questions to determine if the game is fair. 1. How many outcomes does the game have? (9) 2. Label each possible outcome on tree diagram as to win for A, B or tie. 3. Count wins for A (3) 4. Find probability A will win in any round (3/9=1/3) Explain what probability means favorable outcomes/ possible outcomes 5. Count wins for B (3) 6. Find probability B will win in any round (3/9) 7. Is game fair? Do both players have an equal probability of winning in any round? (Yes) 7. Compare the mathematical model with what happened when the students played the game. Go to summary. Time permitting play another game Play game again using 3 students. Using the following rules: 1. A wins if all 3 hands are same. 2. B wins if all 3 hands are different. 3. C wins if 2 hands are same. There will be 27 outcomes this time. 3 to the third power.

3*3*3=27 Closure/Summary: Question individual students by asking, “What did we learn today?” If any objectives aren’t brought up, question further until all objectives have been covered. Ask “Do you think knowing probabilities is important” Assessment: Teacher observation and exit card. Exit card will include the following questions. What is the rule for probability? Draw a tree diagram for the 3 person game. Adapted from Shirley LeMoine , Garfield Re-2 School District, Rifle, Co