The document discusses probability and ordering events on a probability scale. It defines probability as a measure of how likely something is to happen. An event that is certain has a probability of 1, an impossible event has a probability of 0, and an even chance event has a probability of 1/2 or 50%. Examples are provided to demonstrate applying the probability scale. The document also includes word problems about the probability of selecting certain students from a class.

1. ORDERING EVENTS
By Mr. Reale

2. The Probability Scale
Probability measures how LIKELY something is to happen.
An even that is certain to happen has a probability of 1.
An event that is impossible has a probability of 0.
An event that has an even or equal chance of occurring has a
probability of ½ or 50%.

3. The Probability Scale
What does 1 mean on the probability scale?
What does ½ or 50% means on the probability
scale?
What does 0 mean on the probability scale?

4. Example 1
Event Probability
The month after May will be November.
You will get an even number when you roll a single die.
The year after 1999 was 1996.
Mrs Henderson will have a girl.
The day after Saturday will be Sunday.

5. Example 2
There are 25 students in Mrs Henderson’s Year 5/6 class.
Of the 25 students, 10 support the West Coast Eagles, 6
support Collingwood, 5 support the Fremantle Dockers and
the rest support Port Adelaide.
a.) How many Port Adelaide supporters are there? _____
b.) If I were to pick one student at random what would be
the probability that they would support the W.C.E.?
Probability = ____

6. Example 2 (continued)
There are 25 students in Mrs Henderson’s Year 5/6 class.
Of the 25 students, 10 support the West Coast Eagles, 6
support Collingwood, 5 support the Fremantle Dockers and
the rest support Port Adelaide.
3.) What is the probability that I pick a student at random
and they support the Fremantle Dockers?
Probability = ____ = ____
Simplify

7. Your turn Year 5/6…
1.) Complete activity 1: Chance and probability –
ordering events.
2.) Complete activity 2: Chance and probability –
probability scale.
3.) Mathletics – complete Chance activity modules.
Working towards doing the Mathletics test. 