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’ and its extension to include lizard and Spock. Digital simulations and hands-on options for the game are given for variety.

In a prior lesson, students can complete repeated trials of the game ‘Rock, paper, scissors’.

Rock, paper … lizard, Spock? Image

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


Digital literacy

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

The following activity is a suggested opportunity for formative assessment.

Reserve time in the lesson to play the downloadable Matching activity: assessing understanding of the language of experimental and theoretical probability, random and the law of large numbers.

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 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.
  • Some students 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)

  • Lizard, Spock recording sheet (Word)

  • Lizard, Spock card cutouts (Word)

  • Matching activity (Word)

  • Small opaque bags per group, laptops/tablets for each student