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.

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

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 2 + 7 = 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 2 + 7 = 9 A year when it does not rain Going without Food and drink for a year. Start

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

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

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 √ ² 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 - . = +

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

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

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

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

Colour from a bag Blue beads Probability of a Blue Favourable = Possible = (-) Ans On C √ ² 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 . = +

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 √ ² 14 1 15 7 9 11 13 7 8 9 x 16 4 5 6 ÷ 1 2 3 - spin Next Example . = + Win

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

= = = 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

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

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

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

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

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