Welcome to the Revision Conference Name: School: Session 1 - Data Sampling & Questionnaires Stem-and-leaf Scatter Graphs Frequency Polygons Sampling Comment on these sampling techniques You want to find out how much exercise people in your town do. You go to the local sports centre to carry out a survey You want to work out what proportion of a magazine is pictures. You count the number of pictures on the first 3 pages Questionnaires – Important Points Normally 2 parts to an exam question: Critique a questionnaire – say what is wrong Improve a questionnaire Questionnaire involves: (1) A question (2) Response boxes Questions: Must state a time period e.g. per day, per week, per month etc Response Boxes: Must NOT overlap Is there a zero or more than option? Options must mean the same thing to everyone (a lot, excellent, not much are NOT GOOD numerical options are normally better) Questionnaires Critique & Improve: “How much money do you spend on magazines?” State TWO criticisms: Improve this questionnaire: Questionnaires Critique & Improve: “How many pizzas have you eaten?” State TWO criticisms: Improve this questionnaire: Questionnaires Critique & Improve: “How many DVDs do you watch?” State TWO criticisms: Improve this questionnaire: The data below represents test results for 16 students in year 11. Stem and Diagram 7 15 38 13 Stem (tens) 0 1 2 3 4 41 23 22 45 Leaf (units) 20 17 8 11 5 17 24 30 Interpreting Stem (tens) Leaf (units) Key 2 | 3 = 23 1 0 5 5 7 2 1 4 6 7 8 (a) Mode 3 1 2 2 2 5 78 4 3 7 (b) Median 5 1 4 8 (a) Range Scatter graphs What can you expect…….. • Plot (extra) coordinates • Describe the correlation • Draw a line of best fit • Use you line of best fit to estimate values BE CAREFUL OF SCALES Scales Plot (10, 1000) (3, 500) (8, 600) (11, 750) Weight (kg) Describe the Correlation 60 55 50 45 40 140 150 160 170 Height (cm) 180 190 Life expectancy 85 80 75 70 65 60 55 50 0 20 40 60 80 100 Number of cigarettes smoked in a week 120 Correlation Decide whether each of the following graphs shows, 25 A 20 B 12 10 15 8 positive correlation 6 10 4 5 2 0 0 5 10 15 20 25 0 0 2 4 6 8 10 12 25 25 C 20 D 20 15 15 negative correlation 10 10 5 5 0 0 0 5 10 15 20 25 20 5 10 15 20 25 25 25 E 20 zero correlation 0 F 20 15 15 10 10 5 5 0 0 5 10 15 20 25 0 0 5 10 15 20 25 This graph shows the relationship between student’s results in a non-calculator and a calculator paper If a student scored 74 in the Calculator paper, what would be a good estimate for their non calculator paper? Calculator paper 85 80 75 70 65 60 55 50 0 20 40 60 Non calculator paper 80 100 The table shows this information for two more Saturdays. Maximum outside temperature (C) 15 24 Number of People 80 260 1. Plot this information on the scatter graph. 1. What type of correlation does this scatter graph show? 1. Draw a line of best fit on the scatter graph. The weather forecast for next Saturday gives a maximum temperature of 17. 4. Estimate the number of people who will visit the softball playground. On another Saturday, 350 people were recorded to have visited the playground. 5. Estimate the maximum outside temperature on that day. Frequency Polygons Plot the MID POINT with the frequency Join points with a ruler. Modal Class You Try 60 students take a science test. The test is marked out of 50. This table shows information about the students’ marks Science Mark 0<m≤10 10<m≤20 20<m≤30 30<m≤40 40<m≤50 Frequency 13 17 19 7 4 (a) What is the modal class? (a) Draw a frequency polygon to represent this information Session 2 - Algebra Simplifying Substitution Expanding Brackets Rules of Indices Collecting together like terms Simplify these expressions by collecting together like terms. 1) a + a + a + a + a 2) 4r + 6r 3) 5a x 4b 4) 4c + 3d – 2c + d 5) 4x x 3x 6) r x r x r x r Rules of Negatives Multiplying/Dividing Same sign + Positive Different sign – Negative 3x4 -3 x -4 -3 x 4 3 x -4 Adding/Subtracting Look at “touching” signs Same sign + Positive Different sign – Negative 20 +– 6 = 20 - - 6 = -20 - + 6 = = = = = Substitution Example 4a + 3b a=5 b = -2 Practice: a = 3, c = 2, x = -4 a) 5c b) 3x c) 4c + 5a d) c – x e) 5a + 2x 2 f) 3c g) x2 Plotting graphs of linear functions y = 2x + 5 x –3 –2 –1 0 1 2 3 y = 2x + 5 1) Complete the table and plot the points y 2) Draw a line through the points 3) Use you graph to estimate: (i) y when x = - 1.5 (ii) x when y = 8 3 2 1 1 2 3 x y = 2x + 2 Use your graph to estimate the value of y when x = -1.5 Linear Graphs – NO Table Given – Make one On the grid draw the graph of x + y = 4 for values of x from -2 to 5 Expanding Brackets Look at this algebraic expression: 3(4x – 2) To expand or multiply out this expression we multiply every term inside the bracket by the term outside the bracket. 3(4x – 2) = (a)3(x + 5) (b)12(2x – 3) (c)4x(x + 1) (d)5a(4 – 7a) Expanding Brackets and Simplifying Expand and simplify: 2(3n – 4) + 3(3n + 5) Expand and simplify: 3(3b + 2) - 3(2b - 5) Expanding DOUBLE brackets (x + 4)(x + 2) x x 2 x 4 Expanding two brackets Expand these algebraic expressions: (x + 5)(x + 2) = (x + 2)(x - 3) = Indices When we multiply two terms with the same base the indices are added. a4 × a2 = 4a5 × 2a = When we divide two terms with the same base the indices are subtracted. a5 ÷ a2 = 4p6 ÷ 2p4 = When we have brackets you need to multiply the indices. (y3)2 = (q2)4 = You Try 1) a2 x a3 = 2) m2 x m-4 = 3) 3h2 x 4h = 4) 3g-5 x 2g-3 = 5) a5 ÷ a3 = 6) m3 ÷ m = 7) 10h 2 ÷ 5h 3 = 8) 12g5 ÷ 3g-3 = 5 3 9) a x a = 10) (a2)3 = a2 11) (m3)-4 = 12) (g-5)-3 = Session 3 - Shape Transformations Pythagoras’ Theorem Pythagoras There are two ways you have to answer this question: (1) Finding the longest side (2) Finding a shorter side Pythagoras Draw and label these lines Transformations Find Reflections State pairs of triangles and the equation of the line Now reflect the black triangle in the line x = y Translation Can describe in words: Or as a VECTOR Translations Rotations (a) Rotate triangle T 90 anti-clockwise about the point (0,0). Label your new triangle U (a) Rotate triangle T 180 about point (2,0). Label your new triangle V Transformations Describe fully the single transformation which maps triangle T to triangle U 3 Marks = 3 THINGS Transformations Describe fully the single transformation which maps triangle A to triangle B 3 Marks = 3 THINGS DESCRIBING Rotations Describe (3 marks) Enlargements Describe fully the single transformation which maps shape P to shape Q Enlargements Describe fully the single transformation which maps triangle S to triangle T Session 4 - Number BIDMAS Long Multiplication Place Value Estimating Fractions BIDMAS (a) 6 x 5 +2 (b) 6 + 5 x 2 (c) 48 ÷ (14 – 2) (d) 2 + 32 (e) 6 x 4 – 3 x 5 (f) 35 – 4 x 3 B( ) I x2 D ÷ M x A + S - Long Multiplication One more for you to try….. 46 x 129 = Long Multiplication – Embedded into a word problem I buy 135 tickets costing £12 each. How much do I spend? Using this information 46 x 129 = Calculate: (a)4600 x 129 (b)46 x 12.9 (c)460 x 1290 (d)4.6 x 1290 (e)4.6 x 0.129 = = = = = Using this information 46 x 129 = 5934 Calculate: 5934 ÷12.9 Estimate: = Using this information 97.6 x 370 = 36112 Calculate: (a)9.76 x 37 (b)9760 x 3700 (c)361.12 ÷ 97.6 Rounding to ONE significant figure to 1 s. f. 4 890 351 6.3528 34.026 0.0007506 0.005708 150.932 0.00007835 Estimate: 43 x 2.6 = (3.01 + 8.7)2.2 = Estimate: 7 .8 5 .3 10 . 3 68 401 198 What if you need to divide by a decimal? Work out an estimate for the value of 6.37 x 1.9 0.145 412 5 . 904 0 . 195 5 . 79 312 0 . 523 Multiplying Fractions 3 4 What is × 8 5 What is ? 5 2 × 6 5 ? Dividing Fractions 4 2 What is ÷ ? 5 3 What is 6 3 ÷ ? 7 5 Adding and Subtracting Fractions What is What is 1 1 + ? 2 3 3 3 + ? 5 4 Fractions How to score HIGH marks Where to start with topics……. 2nd March NON Calculator 5th March CALCULATOR • Estimating (round to 1 significant figure) •Trial and Improvement • Place Value •Use your calculator to work out…… • Solving Linear Equations •Rounding - decimal places and sig figs • Long Multiplication and Division •Area and circumference of a circle •Volume and surface area of cylinders • Fractions Operations (+, - , x, ÷) • Indices •Pythagoras’ Theorem • Substitution •Currency Conversions • Transformations (doing and describing) • Expanding Brackets and factorising • Angles (parallel lines, special triangles) • Simple percentage increase/decrease • Plans and Elevations (& planes of symmetry) • Writing and using formulae • Questionnaires How to score HIGH marks What should be my strategy in the exam hall for MATHS? Depends if you are higher or foundation If you are entered for higher – it is worth revising some “easy” B grade topics • • • • • Tree Diagrams Cumulative Frequency Basic Circle Theorems Right – angle Triangle Trigonometry Standard Form How to score HIGH marks If the question asks you to calculate: AREA – immediately write ……… on the answer line VOLUME – immediately write …… on the answer line Factorise “fully” – clue that there is more than one factor e.g. Factorise fully 8x + 12x2 Trial and Improvement - Once you have the this situation…. X 2.7 2.8 ----- Too small ----- Too big Circles x 9.72 = 295.5924528 Pythagoras 82 + 112 = 64 +121 = 185 √185 = 13.60147051 Use your calculator to work out the value of 6 . 27 4 . 52 4 . 81 9 . 63 (a) Write down all the figures on your calculator display. 1.962631579 .......................... (2) (b) Write your answer to part (a) to 3 decimal places ..........................(1) (Total 3 marks)