Chance — South Australian Year 4 Maths
Comparing how likely events are, fair games, repeated chance experiments, expected and observed results, and independent events. Two subtopics and 40 questions with answers, aligned to AC9M4P01 and AC9M4P02.
Chance in South Australian Year 4
This topic is about how likely things are to happen. Students compare outcomes as more likely, less likely or equally likely and decide whether a game is fair, then repeat experiments with spinners, coins and dice to compare expected and observed results and see when one result affects the next.
The two subtopics below are comparing the chance of events, and repeated chance experiments and independent events. Chance is one of the 20 topics in South Australian Year 4 Maths and sits in the Probability strand. It covers Australian Curriculum codes AC9M4P01 and AC9M4P02. Comparing chances in words leads on to describing chance with numbers in later years.
Subtopics
Chance: common questions
How do you decide which outcome is more likely?
Count how much of each outcome there is. A spinner with 5 equal parts, 3 blue and 2 orange, is more likely to stop on blue than on orange. If there is the same amount of each, the outcomes are equally likely.
What makes a game fair?
A game is fair when every player has the same chance of winning. If Sara wins on red and Tom wins on blue, the spinner needs as much red as blue. A spinner with 6 equal parts, 4 red and 2 blue, is not fair, because red will usually come up more often.
Why don’t the results match what we expect?
Expected results tell you what should happen on average, but real results vary. Tossing a fair coin 40 times, you expect about 20 heads, yet getting 18 or 23 is quite normal. The more times you repeat an experiment, the closer the results usually get to what you expect.
What are independent events?
Two events are independent when the first result does not change the chance of the second. A die has no memory, so rolling a 6 does not make the next 6 more or less likely. Taking a counter from a bag and not putting it back is different: the bag has changed, so the second draw depends on the first.
Which curriculum codes cover Chance in South Australian Year 4?
The topic covers Australian Curriculum v9 codes AC9M4P01 (describing and ordering how likely events and outcomes are, and telling independent from dependent events) and AC9M4P02 (running repeated chance experiments and describing how the results vary).