Teacher notes

• It is important to develop a shared understanding or vocabulary. One way to do this is to use a continuum and have students indicate where along this continuum of probability they feel words should be placed. The purpose of this activity is to have some discussion around the meaning of each word so that the class shares a common understanding of each.
• Students, particularly those who have active imaginations, can find it difficult to declare an event absolutely certain or completely impossible. Using a continuum allows students to concede that an event is virtually impossible and reduces distracting speculation about situations in which an event might or might not occur.
• Encourage students to identify all possible outcomes before beginning a probability experiment, for example when tossing a conventional die the outcome will be either 1,2,3,4,5,6. It is important that students also identify outcomes which are not possible. For example, when pulling a cube from a bag which has red, blue and green counters, it will not be possible to draw out a yellow counter, even if that is someone’s favourite colour!
• Encourage students to predict an outcome and explain why they think this will happen. Students often look to past experiences or for a pattern upon which they can base their predictions rather than seeing each trial as an independent event. Misconceptions are often only evident when they justify their position. One common misconception that may arise is the belief that it is more difficult to throw a 6 on a die. This is because waiting to throw a six before moving at the beginning of a board game can seem to take a long time. Another misconception is that there is a pattern to outcomes. So throwing a coin and expecting to get Head, Tail, Head, Tail …. Alternatively, if the pattern is Head, Head, Head … they may expect either another Head (continuing the pattern) or Tail (to break the pattern and keep a balance closer to the theoretical or ‘fair’ outcome).