What is Probability Learning Intention 1 To understand

What is Probability Learning Intention 1. To understand the likelihood line and calculating simple probability. Success Criteria 1. Understand the term likelihood line and probability. 2. Decide where certain events should lie on the likelihood line. 3. Calculate simple probabilities.

What is Probability Likelihood Line Probability is a measure of how likely an event is to happen 0 Impossible Seeing a butterfly In July 0. 5 Not very likely School Holidays Evens Winning the Lottery 1 Very likely Baby Born A Boy Certain Go back in time

What is Probability Likelihood Line 0 0. 5 Impossible Not very likely Evens Click the statement which is It will Snow in winter Start The answer to 2+7=9 1 Very likely Certain Impossible A year when it does not rain Toss a coin That land Heads Going without Food and drink for a year.

Calculating 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) Probability of an event happening= number of favourable outcomes number of possible outcomes

Heads or Tails The coin was spun twenty times. Number of Heads 9 Number of Tails 11 Result …. . 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 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 Experiment … Number of times to toss coin Number of Heads 58 Number of Tails 42 100 0 100 Try Again You are as likely to get a Heads as you are to get Tails (-) Ans On C √ ² 7 8 9 x 4 5 6 ÷ 1 2 3 0 . - = +

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 Win ( Favourable ) Could get Possible Could win right away but much more likey to lose

How to calculate Probability of “Heads” Possible Favourable Probability is a Maths term which allows you to predict how likely Whatcould you happen want an event ( head on a coin ) is to happen Probability = Favourable Outcomes 1 = 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 0 1 2 1

Probability of a six Probability is a Maths term which allows you to predict how likely an event ( like rolling a six ) is to happen Favourable Outcomes Probability = 1 = 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 0 1 6 1

Getting an even number on a dice Favourable Outcomes Probability = 3 = Possible Outcomes 6 = 1 2 Will Happen Will not Happen 0 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 = 0 (-) Blue 4 Orange 1 Yellow 4 Red 3 New Example Click beads to put in bag Click Name to select colour Ans On C √ ² 7 8 9 x 4 5 6 ÷ 1 2 3 0 . - = +

Spinner 1 to 16 9 8 Probability of a 7 Odd = 6 8 Favourable 16 Possible 5 10 = 4 11 1 2 3 12 13 2 14 spin 15 Win 1 16 Next Example 0 Favourable 15 3 1 5 7 9 11 13 (-) Ans On C √ ² 7 8 9 x 4 5 6 ÷ 1 2 3 0 . - = +

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 Probability of a Red = Possible Outcomes = Favourable Outcomes Probability of a Spade = Possible Outcomes = 2 4 1 4 = 1 2

Pack of Cards A pack of cards should have 52 cards. 4 suits ( sets ) of 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 Probability of Heart Favourable Outcomes = Possible Outcomes One row out of four = 13 52 = 1 4

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

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

0 (-) Ans On C √ ² 7 8 9 x √ ² C x ÷ 5 6 7 8 9 + - On 0 1 2 3 4 . = Ans (-) 0 4 5 6 ÷ 1 2 3 0 . - = +