Topics
15. Chance
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Australia
Year 3

15.02 Outcomes

Lesson
Practice
Lesson

Are you ready?

Can you remember the words we can use to  describe chance  ?

Examples

Example 1

What is the chance of winning the lottery?

A
Impossible
B
Unlikely
Worked Solution
Create a strategy

Think about if it is possible to win the lottery.

Apply the idea

Winning the lottery does happen but it is extremely rare. So it is unlikely to win the lottery. So the answer is option B.

Idea summary

These are the 4 terms we have seen to describe chance:

  • Impossible: definitely will NOT happen.
  • Unlikely: more likely NOT to happen than to happen.
  • Likely: more likely to happen than not to happen.
  • Certain: definitely will happen.

Spinners

Spinners are a popular way to explore chance, this video shows you what a spinner is and how to use it and work out what it means.

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Examples

Example 2

If you spin this spinner:

A spinner with 3 apples, 2 pigs, 2 balls, and 1 star on it.
a

What is a possible outcome?

A
An image of an elephant.
B
An image of a ball.
Worked Solution
Create a strategy

Select the symbol that appears on the spinner.

Apply the idea

The ball appears on the spinner, so it is the possible outcome. The correct answer is option B.

b

What is the likelihood of spinning an apple?

A
Unlikely
B
Likely
Worked Solution
Create a strategy

Count the number of the apple on the spinner and compare it to the total number of symbol that appears on the spinner.

Apply the idea

There is 3 apple symbol out of 8 symbols in the spinner. 3 out of 8 is not too many, since 3 is less than half of 8.

So it is unlikely to spin an apple, option A.

Idea summary

When spinning a spinner:

  • An outcome is only possible if it appears on the spinner.

  • An outcome is likely if more than half the parts of the spinner have that outcome.

  • An outcome is unlikely if less than half the parts of the spinner have that outcome.

Dice

This video shows us everything we need to know about dice.

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Examples

Example 3

A six-sided die is rolled.

An image of a six sided die.

Which of the following is not a possible outcome?

A
Rolling a multiple of ten
B
Rolling a three
Worked Solution
Create a strategy

The possible outcomes are the numbers that appear on a die.

Apply the idea

A die has 1, 2, 3, 4, 5, and a 6 on it only. So rolling a multiple of ten is not a possible outcome.

The answer is option A.

Idea summary

A six sided die has 1, 2, 3, 4, 5, and a 6 on it only. So those numbers are the only possible outcomes when rolling a die.

Other events

This video shows us how to find the likelihood of other types of events.

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Examples

Example 4

These four cards are shuffled. Dave draws one at random and records the shape.

4 cards with a symbol on each card. 1 card has a cross, 2 cards have a heart and 1 has a star.
a

How many different outcomes are there?

Worked Solution
Create a strategy

Count the number of different shapes on the cards.

Apply the idea

There are 3 different shapes: a cross, a star and a heart. So there are 3 different outcomes.

b

What are the chances of drawing a star?

A
Likely
B
Unlikely
Worked Solution
Create a strategy

Count the number of star card and compare it to the total number of cards present.

Apply the idea

There is 1 star card out of 4 cards present. 1 out of 4 is not too many so it is unlikely to draw a star card. The answer is option B.

Idea summary

When we want to work out the chance of something happening, we need to work out all the possible outcomes first. A good way to do that is to think about all the different things that could happen.

Outcomes

AC9M3P01

identify practical activities and everyday events involving chance; describe possible outcomes and events as ‘likely’ or ‘unlikely’ and identify some events as ‘certain’ or ‘impossible’ explaining reasoning

AC9M3P02

conduct repeated chance experiments; identify and describe possible outcomes, record the results, recognise and discuss the variation

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