Presentation on theme: "GCSE Maths Starter 20 Change 3 8 into a decimal"— Presentation transcript:
1 GCSE Maths Starter 20 Change 3 8 into a decimal Q = 2c + d, when c = 3, d = 2. Work out the value of QDraw an ordered stem and leaf diagram, for the data belowUsing the information that 4.8×34= Write down the value of48×344.8×3.4Work out the difference in temperature between 6pm and 10pm
2 Lesson 20 Probability Mathswatch clip (90/91). To list all possible outcomes (Grade D )To calculate missing probabilities from mutually exclusive events (Grade D)
3 Calculating probability If the outcomes of an event are equally likely then we can calculate the probability using the formula:Probability of an event =Number of successful outcomesTotal number of possible outcomesFor example, a bag contains 1 yellow, 3 green, 4 blue and 2 red marbles.Point out that calculated probabilities are usually given as fractions but that they can also be given as decimals and (less often) as percentages.Ask pupils to give you the probabilities (as decimals, fractions and percentages) of gettinga blue marblea red marblea yellow marblea purple marblea blue or a green marble, etc.What is the probability of pulling a green marble from the bag without looking?310P(green) =or 0.3or 30%
4 Calculating probability A fair dice is thrown. What is the probability of gettinga 2?a multiple of 3?an odd number?a prime number?a number bigger than 6?an integer?16a) P(2) =26=13b) P(a multiple of 3) =36=12c) P(an odd number) =
5 Lesson 20 Probability Mathswatch clip (90/91). Work out the probability of:(a)(b)421(i)12P(Red) =(i)P(Odd) =(ii)27P(Green) =(ii)14P(Multiple of 3) =17(iii)(iii)17P(Yellow) =P(>5) =(iv)57(iv)P(<1) =P(Not blue) =3712(v)(v)P(Blue or yellow) =P(Prime) =14(vi)(vi)P(Purple) =P(Square) =5
6 Sample space diagrams 9 6 5 4 8 3 2 1 + Second die First die This table is another way of displaying all the outcomes from throwing two dice and adding them together. It is called a sample space diagram.96548321+Second dieFirst dieFill in the rest of the cells in the table.Colour in all the twos one colour, the threes another colour etc.The completed table appears on the next slide.What patterns do you notice in the table?
7 Sample space diagrams 12 11 10 9 8 7 6 5 4 3 2 1 + Second dieFirst dieWhat is the probability of getting a total more than 5?What is the probability of getting a total less than 10?What is the probability of getting a total that is a square number?What is the probability of getting an even total?What is the probability of getting an odd total?What is the probability of getting a total less than 13?234567345678456789567891067891011789101112
8 Lesson 20 Probability Mathswatch clip (90/91). What is the probability of getting:a total more than 4?a total less than 8?a prime number total?a total that is at least 3?a total of 4 or 5?the same number on both dice?a lower number on the first dice?87654321+Second dieFirst die
9 Lesson 20 Probability Mathswatch clip (90/91). Some for you to try..
10 Lesson 20 Probability Mathswatch clip (90/91). Exam questions