D2.1 Use fractions to express the probability of events happening, represent this probability on a probability line, and use it to make predictions and informed decisions.

Activity 1: Using Fractions to Express Probability


Show students the spinner below divided into eight different coloured parts.

Roulette wheel divided into eight parts. There are two orange parts, one red part, one yellow part, one red part, one yellow part and two red parts. The arrow is located on the last red part.

Represent, as fractions, the probability that the arrow will stop on:

  • orange (since the orange colour occupies a quarter of the circle, the probability that the arrow will stop on this colour is \(\frac{2}{8}\), or \(\frac{1}{4}\);
  • red (since the colour red occupies half of the circle, the probability that the arrow stops on this colour is \(\frac{4}{8}\), or \(\frac{1}{2}\);
  • yellow (since the colour yellow occupies one quarter of the circle, the probability that the arrow will stop on this colour is \(\frac{2}{8}\), or \(\frac{1}{4}\).

Activity 2: Representing a Probability on a Probability Line


Put the values below on the probability line.

\( 0 \ \ \frac{6}{8} \ \ \frac{1}{4} \ \ \frac{4}{8} \ \ \frac{9}{12} \)

The probability line has four sections and five features, namely: Impossible, Somewhat likely, Equiprobable, Very Likely and Certain. The two sections between Equiprobable and Certainty are in dark blue.

Activity 3: Making Predictions Using Probability


Present students with the following situation:

Frederique plays basketball. She makes an average of 5 out of 10 baskets. She makes 4 consecutive attempts. How many baskets do you think she will make? Explain your prediction with a probability.