1. What is Probability Learning Intention Success Criteria
To understand the likelihood line and calculating simple probability.
Understand the term
likelihood line and probability.
Decide where certain events should lie on the
likelihood line.
3. Calculate simple probabilities.

2. What is Probability Likelihood Line 1 0.5
Probability is a measure of how likely an event is to happen 1
0.5
Impossible
Evens
Certain
Not very
likely
Very
likely
Seeing
a butterfly
In July
School
Holidays
Winning the
Lottery
Baby Born
A Boy
Go back
in time

3. What is Probability Likelihood Line 1 0.5 Start Impossible Evens
Impossible
Evens
Certain
Not very
likely
Very
likely
Going without
Food and drink
for a year.
A year when it does not rain
Toss a coin
That land
Heads
The answer to = 9
It will
Snow in winter
Click the statement which is
Impossible
Toss a coin
That land
Heads
It will
Snow in winter
The answer to = 9
A year when it does not rain
Going without
Food and drink
for a year.
Start

4. Calculating Probability
Probability can be thought of as a simple fraction or decimal.
It always lies between 0 and 1.
0 meaning impossible ( could not happen)
1 meaning certain ( will definitely happen)
number of favourable outcomes
Probability of an event happening=
number of possible outcomes

5. Heads or Tails The coin was spun twenty times. Result …..
Number of Heads 9
Number of Tails 11
About as many Heads as Tails
The likelihood of getting a Head is evens … or … half …. Or 0.5
Heads or Tails
Restart

6. Head or Tail 100 You tossed a coin and got a HEAD
You still have an even chance of getting a HEAD next time
It is only when you toss the coin a large number of times that the results shout “even” themselves out
100
Experiment … Number of times to toss coin
100
Number of Heads 58
(-)
Ans On
Try Again C √
Number of Tails 42 7 8 9 x
You are as likely to get a Heads as you are to get Tails 4 5 6 ÷ 1 2 3 - . = +

7. Could win right away but much more likey to lose
Rolling a Dice
When you roll a dice you could get …..
To win a game you need a six. How likely is this ?
To win
Could get
Win
( Favourable )
Possible
Could win right away but much more likey to lose

8. How to calculate Probability of “Heads”
Favourable
What you want
Possible
What could happen
Probability is a Maths term which allows you to predict how likely an event ( head on a coin ) is to happen
Favourable Outcomes 1
Probability = =
Possible Outcomes 2
Probability expressed as a fraction. Why ?
The line shows that there is an even chance of getting a head
Fractions go from 0 ( unlikely to happen) to 1 ( must happen )
Will Happen
Will not Happen 1 2 1

9. Probability = = Probability of a six Favourable Outcomes 1
Probability is a Maths term which allows you to predict how likely an event ( like rolling a six ) is to happen
Favourable Outcomes 1
Probability = =
Possible Outcomes 6
Probability expressed as a fraction. Why ?
The line shows that getting a six immediately is unlikely but possible
Fractions go from 0 ( unlikely to happen) to 1 ( must happen )
Will Happen
Will not Happen 1 6 1

10. Getting an even number on a dice
Favourable Outcomes 3 1 = =
Probability =
Possible Outcomes 6 2
Will Happen
Will not Happen 3 6 1
You have an equal chance of getting an even number

11. Colour from a bag Blue beads Probability of a Blue Favourable =
Possible =
(-)
Ans On C √
Blue 4
Orange 1 7 8 9 x 4
Red 3 4 5 6 ÷
Yellow 1 2 3 -
Click beads to put in bag
Click Name to select colour
New Example . = +

12. Spinner 1 to 16 Probability of a Odd 8 7 Favourable 8 = 9 6 16
Possible 10 5 1 = 11 4 2 12 3
Favourable 13 2
(-)
Ans On 15 3 1 5 C √ 14 1 15 7 9 11 13 7 8 9 x 16 4 5 6 ÷ 1 2 3 -
spin
Next Example . = +
Win

13. Calculating Probability
Example : A boy tossed a coin.
What is the probability that it is heads.
Example : There are 3 red and 4 green balls in a bag.
What is the probability a green ball is picked.
Favourble
Possible

14. = = = Choosing from 4 cards The Heart and Diamonds are Red
The Club and Spades are Black
Favourable Outcomes
Possible Outcomes 2 1 = =
Probability of a Red = 4 2
Probability of a Spade =
Favourable Outcomes
Possible Outcomes 1 = 4

15. Pack of Cards
A pack of cards should have 52 cards. 4 suits ( sets ) of 13 cards
13 cards with SPADES on them. SUIT of cards
Ace of CLUBS can be worth 1 or 11
Queen of HEARTS is a FACE card. Worth 10
2 of DIAMOND is the lowest value diamond

16. = = = Pack of Cards : A Heart Favourable Outcomes Possible Outcomes 13
Probability of Heart = = = 52 4
One row out of four

17. Pack of Cards : Face Card
Favourable Outcomes
Possible Outcomes 12 3
Probability of Face Card = = = 52 13
Three columns out of thirteen
A Face Card shows a characters face … J, Q or K

18. Pack of Cards : Less than four
Favourable Outcomes
Possible Outcomes
Probability of a number less than 4 8 2 = = = 52 13
Two columns out of Thirteen
Ace High … Ace counts as 11

19. (-)
Ans On C √ 7 8 9 x
(-) √ C x ÷ 4 5 6 ÷ 5 6 7 8 9 + - On 1 2 3 - 1 2 3 4 . =
Ans . = +