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Australia
Year 4

11.02 Outcomes

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

Terms to describe chance:

  • Impossible: definitely will NOT happen.

  • Unlikely: more likely NOT to happen than to happen.

  • Even chance: one thing is not more likely to happen than the other

  • 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 the most likely symbol to spin?

A
Pig
B
Ball
C
Apple
Worked Solution
Create a strategy

Count how many times each option appears on the spinner.

Apply the idea

The pig and ball appear on the spinner twice, while the apple appear three times.

So, the apple is the most likely symbol to spin.

The correct answer is option C.

b

What is the likelihood of spinning an apple?

A
Unlikely
B
Likely
Worked Solution
Create a strategy

Count the number of apples on the spinner and compare it to the total number of symbol that appear on the spinner.

Apply the idea

There are 3 apple symbols 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.

What are the chances that the outcome is odd?

A
Unlikely
B
Even chance
C
Likely
Worked Solution
Create a strategy

Count how many odd numbers there are on a die and compare it to the number of sides of a die.

Apply the idea

A die has the numbers 1, 2, 3, 4, 5,6 on it. There are 3 odd numbers on a die: 1,3, 5.

Since 3 is half of 6, we have an even chance of rolling an odd number.

The answer is option B.

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

You draw one marble out of this jar without looking:

A jar with 5 black, 7 red, and 8 blue marbles.

Which marble is more likely to be selected?

A
Black marble
B
Red marble
Worked Solution
Create a strategy

Compare the number of black marbles with the number of red marbles.

Apply the idea

There are 5 black marbles and 7 red marbles in the jar. Since there are more red marbles, it is more likely to select a red marble.

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

ACMSP092

Describe possible everyday events and order their chances of occurring

ACMSP093

Identify everyday events where one cannot happen if the other happens

ACMSP094

Identify events where the chance of one will not be affected by the occurrence of the other

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