Year level: 7

Strand: Probability

Lesson length: 50 mins

In this lesson, students compare theoretical and experimental probabilities by completing repeated trials of the game ‘Rock, paper, scissors’.

In a follow-up lesson students complete repeated trials of the game ‘Rock, paper, scissors’ with extensions to include lizard and Spock.

### Achievement standard

By the end of Year 7, students conduct repeated single-step chance experiments and run simulations using digital tools, giving reasons for differences between predicted and observed results.

### Content description

Students conduct repeated chance experiments and run simulations with a large number of trials using digital tools; compare predictions about outcomes with observed results, explaining the differences. AC9M7P02

### General capabilities

Numeracy

Digital literacy

• Acquiring and collating data (Level 5)
• Interpreting data, selecting (Level 5)
• Select and operating tools (Level 5)

The following opportunity for assessment is suggested for this lesson.

Download, print and pre-cut the exit tickets and distribute them to students. They can be accessed in the What you need section.

• Calculate! If a player consistently chooses rock every time, what is the probability that they will win against an opponent who chooses randomly?
• Explain! Explain the law of large numbers in your own words and how you saw this in today’s lesson.

It is assumed that students have knowledge of expressing probabilities as a fraction, decimal or percentage.

Language:

• Equally likely outcomes
• Chance experiment
• Relative frequency
• Trial
• Experimental probability
• Some students may have misconceptions about what is fair. Although in the whole-class game, from the outset students have an equal chance of being crowned the class champion, students might think the game is unfair if they immediately lose in their first game and so only get one go at the game.
• Students may think that a predictable sequence like ‘scissors-scissors-scissors’ or ‘rock-paper-scissors-rock-paper-scissors’ is less likely to win compared to a random sequence (in a game where the opponent chooses randomly), which is a common misconception although each individual random sequence is just as likely or unlikely as these two that show a pattern.
• Students may believe that they can make random choice and think that they are good at making random choices, failing to recognise the inherent bias. Include instruction to guide the student to overcome the misconceptions.

## What you need:

• Lesson plan (Word)

• Teacher's slides (PowerPoint)

• Rock paper scissors recording sheet (Word)

• Exit ticket (Word)

• Laptops/tablets for each student