We often use the language of probability in conversation – “There’s a good chance of rain today” or “He is almost certain their team will win”. In mathematics, we can give precise values to the probability of a particular event occurring, ranging from 0 for impossible to 1 for certain. Draw a number line across your page, labelled zero at left and 1.0 and 100% at right. Mark 0.25; 0.50 and 0.75 on your line. Now match ‘likely’, ‘even chances’ and ‘unlikely’ on your line. Label where you think the following events will be:

- Essendon winning the coin toss at the beginning of the game
- Snow falls in Darwin
- Drawing a red heart card from a shuffled pack
- Rolling a six on a die
- A baby is born – it’s a girl!
- The sun rises in the east tomorrow
- Water boils in the fridge
- A horse wins the Melbourne Cup
- Mrs Gow winning Australian Idol