pemberton mathematics
TRANSCRIPT
Oxford excellence for Cambridge IGCSE®
Sue Pemberton
Pemberton
Mathematicsfor Cambridge IGCSE®
Third Edition
Extended
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Contents
Unit 1 Unit 2Number Order of operations 2 Percentages 1 50
Directed numbers 3 Ratio 52Multiples, factors, primes, squares
and cubes 5Four rules for fractions 10Significant figures and decimal places 14
Algebra Simplifying algebraic expressions 17 Indices 1 58 Solving linear equations 20 Solving linear inequalities 62Constructing formulae 24 Manipulating algebraic fractions 64Substitution into formulae 25 The general equation of a straight line 68Gradients and straight line graphs 28 Representing linear inequalities
on graphs 72
Shape and Space Angle properties 33 Perimeter and area 76Symmetry 36 Pythagoras 78Polygons 39 Area and circumference of a circle 84
Probability and Statistics Averages and range 41 Displaying data 90Frequency tables 44
Examination-style questions 46 Examination-style questions 94
Syllabus matching grid vAbout this book 1
Unit 3 Unit 4Standard form 98 Percentages 2 162
Simultaneous equations 1 102 Expanding double brackets 164Factorising 1 108 Quadratic graphs 168Rearranging formulae 1 112
Similar triangles 114 Bearings 174Reflections, rotations and translations 122 Trigonometry 178Enlargements 138 Angles of elevation and depression 192Surface area and volume 1 144
Probability 1 150 Scatter diagrams 194
Examination-style questions 158 Examination-style questions 198
Number
Algebra
Shape and Space
Probability and Statistics
III
Contents
Unit 8 Unit 9 Unit 10Rational and irrational numbers 358 Compound interest and exponential Upper and lower bounds 434 growth and decay 390
Solving quadratic equations using Simultaneous equations 2 394 Simultaneous equations 3 438 the formula 360 Linear programming 396 Differentiation 443Further algebraic fractions 364 Solving quadratic equations by Expanding more than two brackets 463
Variation 366 completing the square 400 Trigonometric equations and graphs 469 Finding turning points of quadratics by completing the square 404 Using graphs to solve equations 407
The sine and cosine rules 374 Vectors and vector geometry 412 Circle theorems 2 474 Distance from a point to a line 478
Histograms 382 Probability 3 424 Stem-and-leaf diagrams 481 Box-and-whisker plots 487
Examination-style questions 386 Examination-style questions 428 Examination-style questions 492
Answers 498 Index 558 Access your support website for extra exam revision material
and presentations www.oxfordsecondary.com/9780198424802
Unit 6 Unit 7 Percentages 3 248 Distance–time graphs 314 Speed, distance and time 252 Speed–time graphs 318
Sets and Venn diagrams 256 Rearranging formulae 2 322 Indices 2 268 Sequences 324 Solving quadratic equations Exponential graphs 334 by factorisation 272 Reciprocal graphs 276 The gradients of perpendicular lines 278
Circle theorems 282 Sine and cosine ratios for angles up to 180° 338 Area of a triangle 340
Probability 2 296 Cumulative frequency 344
Examination-style questions 304 Examination-style questions 352
Unit 5Direct and inverse proportion 202Increase and decrease in a given ratio 206
Functions 208Factorising 2 214Cubic graphs 218
Surface area and volume 2 222Areas of similar shapes 230Volumes of similar objects 234
Grouped frequency tables 238
Examination-style questions 242
IV Contents
Syllabus topic Page numbers in student book
E1: NumberE1.1 Identify and use natural numbers, integers (positive, negative
and zero), prime numbers, square numbers, common factors and common multiples, rational and irrational numbers, (e.g. π, 2 ) real numbers, reciprocals.
3–9, 358–359
E1.2 Use language, notation and Venn diagrams to describe sets and represent relationships between sets. Definition of sets e.g. A = {x: x is a natural number}, B = {(x,y): y = mx + c}, C = {x: a ≤ x ≤ b}, D = {a, b, c, …}
256–267
E1.3 Calculate with squares, square roots, cubes and cube roots and other powers and roots of numbers.
Embedded throughout book
E1.4 Use directed numbers in practical situations. 3E1.5 Use the language and notation of simple vulgar and decimal
fractions and percentages in appropriate contexts. Recognise equivalence and convert between these forms.
10–13
E1.6 Order quantities by magnitude and demonstrate familiarity with the symbols =, ≠, >, <, ≥, ≤
62–63
E1.7 Understand the meaning of indices (fractional, negative and zero) and use the rules of indices. Use the standard form A × 10n where n is a positive or negative integer, and 1 ≤ A < 10.
58–61, 98–101, 268–271
E1.8 Use the four rules for calculations with whole numbers, decimals and fractions (including mixed numbers and improper fractions), including correct ordering of operations and use of brackets.
2, 10–13
E1.9 Make estimates of numbers, quantities and lengths, give approximations to specified numbers of significant figures and decimal places and round off answers to reasonable accuracy in the context of a given problem.
14–16
E1.10 Give appropriate upper and lower bounds for data given to a specified accuracy. Obtain appropriate upper and lower bounds to solutions of simple problems given data to a specified accuracy.
434–437
E1.11 Demonstrate an understanding of ratio and proportion. Increase and decrease a quantity by a given ratio. Calculate average speed. Use common measures of rate.
52–57, 206–207, 252–255
VSyllabus matching grid
Cambridge IGCSE® Mathematics 0580: Extended
E1.12 Calculate a given percentage of a quantity. Express one quantity as a percentage of another. Calculate percentage increase or decrease. Carry out calculations involving reverse percentages.
50–51, 162–163, 248–251
E1.13 Use a calculator efficiently. Apply appropriate checks of accuracy.
Embedded through out the book
E1.14 Calculate times in terms of the 24-hour and 12-hour clock. Read clocks, dials and timetables.
Embedded through out the book
E1.15 Calculate using money and convert from one currency to another.
204–205
E1.16 Use given data to solve problems on personal and household finance involving earnings, simple interest and compound interest. Extract data from tables and charts.
250–251
E1.17 Use exponential growth and decay in relation to population and finance.
390–393
E2: Algebra and graphsE2.1 Use letters to express generalised numbers and express basic
arithmetic processes algebraically. Substitute numbers for words and letters in formulae. Construct and transform complicated formulae and equations.
17–27, 112–113, 322–323
E2.2 Manipulate directed numbers. Use brackets and extract common factors. Expand products of algebraic expressions. Factorise where possible expressions of the form: ax + bx + kay + kby, a2x2 – b2y2, a2 + 2ab + b2, ax2 + bx + c.
3–4, 18–21, 108–111, 214–217, 463–468
E2.3 Manipulate algebraic fractions. Factorise and simplify rational expressions.
64–67, 364–365
E2.4 Use and interpret positive, negative and zero indices. Use and interpret fractional indices. Use the rules of indices.
58–61, 268–271
E2.5 Derive and solve simple linear equations in one unknown. Derive and solve simultaneous linear equations in two unknowns. Derive and solve simultaneous equations, involving one linear and one quadratic. Derive and solve quadratic equations by factorisation, completing the square and by use of the formula. Derive and solve simple linear inequalities.
20–23, 62–63, 102–107, 272–275, 360–363, 394–395, 400–403, 438–442
E2.6 Represent inequalities graphically and use this representation in the solution of simple linear programming problems.
72–75, 396–399
E2.7 Continue a given number sequence. Recognise patterns in sequences including the term-to-term rule and relationships between different sequences. Find and use the nth term of sequences.
324–333
VI Syllabus matching grid
E2.8 Express direct and inverse proportion in algebraic terms and use this form of expression to find unknown quantities.
366–373
E2.9 Use function notation, e.g. f(x) = 3x – 5, f: x → 3x – 5, to describe simple functions. Find inverse functions f–1(x). Form composite functions as defined by gf(x) = g(f(x)).
208–213
E2.10 Interpret and use graphs in practical situations including travel graphs and conversion graphs. Draw graphs from given data. Apply the idea of rate of change to easy kinematics involving distance–time and speed–time graphs, acceleration and deceleration. Calculate distance travelled as area under a linear speed–time graph.
204–205, 314–321
E2.11 Construct tables of values and draw graphs for functions of the form axn (and simple sums of these) and functions of the form axb + c. Solve associated equations approximately, including finding and determining roots by graphical methods. Draw and interpret graphs representing exponential growth and decay problems. Recognise, sketch and interpret graphs of functions.
168–173, 218–221, 276–277, 334–337, 404–411
E2.12 Estimate gradients of curves by drawing tangents. 170–171E2.13 Understand the idea of a derived function. Use the derivatives
of functions of the form axn, and simple sums of not more than three of these. Apply differentiation to gradients and turning points (stationary points). Discriminate between maxima and minima by any method.
443–462
E3: Coordinate geometryE3.1 Demonstrate familiarity with Cartesian coordinates in two
dimensions.28–32
E3.2 Find the gradient of a straight line. Calculate the gradient of a straight line from the coordinates of two points on it.
28–32, 68–71
E3.3 Calculate the length and the coordinates of the midpoint of a straight line from the coordinates of its end points.
68–71, 82
E3.4 Interpret and obtain the equation of a straight line graph. 28–32, 68–71E3.5 Determine the equation of a straight line parallel to a given line. 68–71E3.6 Find the gradient of parallel and perpendicular lines. 278–281
VIISyllabus matching grid
E4: GeometryE4.1 Use and interpret the geometrical terms: point, line,
parallel, bearing, right angle, acute, obtuse and reflex angles, perpendicular, similarity and congruence. Use and interpret vocabulary of triangles, quadrilaterals, circles, polygons and simple solid figures including nets.
33–35, 39–40, 84–89, 114–121, 148–149, 222–229
E4.2 Measure and draw lines and angles. Construct a triangle given the three sides using ruler and pair of compasses only.
Embedded throughout the book
E4.3 Read and make scale drawings. Embedded throughout the book
E4.4 Calculate lengths of similar figures. Use the relationships between areas of similar triangles, with corresponding results for similar figures and extension to volumes and surface areas of similar solids.
230–237
E4.5 Use the basic congruence criteria for triangles (SSS, ASA, SAS, RHS).
114–116
E4.6 Recognise rotational and line symmetry (including order of rotational symmetry) in two dimensions. Recognise symmetry properties of the prism (including cylinder) and the pyramid (including cone). Use the following symmetry properties of circles:• equal chords are equidistant from the centre• the perpendicular bisector of a chord passes through the centre• tangents from an external point are equal in length.
36–38, 282–295
E4.7 Calculate unknown angles using the following geometrical properties:• angles at a point• angles at a point on a straight line and intersecting straight lines• angles formed within parallel lines• angle properties of triangles and quadrilaterals• angle properties of regular polygons• angle in a semicircle• angle between tangent and radius of a circle• angle properties of irregular polygons• angle at the centre of a circle is twice the angle at the
circumference• angles in the same segment are equal• angles in opposite segments are supplementary; cyclic
quadrilaterals• alternate segment theorem.
33–35, 39–40, 282–295, 374–377
VIII Syllabus matching grid
E5: MensurationE5.1 Use current units of mass, length, area, volume and capacity in
practical situations and express quantities in terms of larger or smaller units.
76–77, 144
E5.2 Carry out calculations involving the perimeter and area of a rectangle, triangle, parallelogram and trapezium and compound shapes derived from these.
76–77
E5.3 Carry out calculations involving the circumference and area of a circle. Solve problems involving the arc length and sector area as fractions of the circumference and area of a circle.
84–89
E5.4 Carry out calculations involving the surface area and volume of a cuboid, prism and cylinder. Carry out calculations involving the surface area and volume of a sphere, pyramid and cone.
144–149, 222–229
E5.5 Carry out calculations involving the areas and volumes of compound shapes.
144–149, 222–229
E6: TrigonometryE6.1 Interpret and use three-figure bearings. 174–177E6.2 Apply Pythagoras’ theorem and the sine, cosine and tangent
ratios for acute angles to the calculation of a side or of an angle of a right-angled triangle. Solve trigonometrical problems in two dimensions involving angles of elevation and depression. Know that the perpendicular distance from a point to a line is the shortest distance to the line.
78–83, 178–193, 478–480
E6.3 Recognise, sketch and interpret graphs of simple trigonometric functions. Graph and know the properties of trigonometric functions. Solve simple trigonometric equations for values between 0° and 360°.
338–339, 469–473
E6.4 Solve problems using the sine and cosine rules for any triangle and the formula area of triangle = ½ ab sin C.
338–343
E6.5 Solve simple trigonometrical problems in three dimensions including angle between a line and a plane.
190–193
E7: Vectors and transformationsE7.1
Describe a translation by using a vector represented by e.g.
xy , AB� ���
or a. Add and subtract vectors. Multiply a vector by a scalar.
130–137, 412–423
E7.2 Reflect simple plane figures. Rotate simple plane figures through multiples of 90°. Construct given translations and enlargements of simple plane figures. Recognise and describe reflections, rotations, translations and enlargements.
122–143
ixSyllabus matching grid
E7.3Calculate the magnitude of a vector
xy as x y+2 2
. Represent
vectors by directed line segments. Use the sum and difference of two vectors to express given vectors in terms of two coplanar vectors. Use position vectors.
412–423
E8: ProbabilityE8.1 Calculate the probability of a single event as either a fraction,
decimal or percentage.150–157
E8.2 Understand and use the probability scale from 0 to 1. 150E8.3 Understand that the probability of an event occurring = 1 – the
probability of the event not occurring.151
E8.4 Understand relative frequency as an estimate of probability. Expected frequency of outcomes.
156–157
E8.5 Calculate the probability of simple combined events, using possibility diagrams, tree diagrams and Venn diagrams.
150–157, 296–303, 424–427
E8.6 Calculate conditional probability using Venn diagrams, tree diagrams and tables.
150–157, 296–303, 424–427
E9: StatisticsE9.1 Collect, classify and tabulate statistical data. 90–93E9.2 Read, interpret and draw simple inferences from tables and
statistical diagrams. Compare sets of data using tables, graphs and statistical measures. Appreciate restrictions on drawing conclusions from given data.
90–93, 194–197, 344–351, 481–491
E9.3 Construct and interpret bar charts, pie charts, pictograms, stem-and-leaf diagrams simple frequency distributions, histograms with equal and unequal intervals and scatter diagrams.
44–45, 90–93, 194–197, 238–241, 382–385, 481–486
E9.4 Calculate the mean, median, mode and range for individual and discrete data and distinguish between the purposes for which they are used.
41–45
E9.5 Calculate an estimate of the mean for grouped and continuous data. Identify the modal class from a grouped frequency distribution.
238–241
E9.6 Construct and use cumulative frequency diagrams. Estimate and interpret the median, percentiles, quartiles and inter-quartile range. Construct and interpret box-and-whisker plots.
344–351, 487–491
E9.7 Understand what is meant by positive, negative and zero correlation with reference to a scatter diagram.
194–197
E9.8 Draw, interpret and use lines of best fit by eye. 194–197
x Syllabus matching grid
This revised edition has been specially prepared to help you achieve your highest potential on the Cambridge IGCSE® Mathematics 0580, extended syllabus. The book is fully up to date and covers the latest syllabus in depth.
The author is an experienced mathematics teacher and an examiner. Packed with carefully chosen examples, helpful tips and plenty of exercises to give you confidence in your abilities, the author’s many years of experience ensure that the book is carefully designed to help you succeed.
The contents are organised into ten units and within each unit the sections are grouped into the broad topics: number, algebra, shape and space, and probability and statistics. Each section concludes with a selection of examination-style questions. A unit is intended to be covered in around 20 hours; this should leave ample time for revision and exam practice if the syllabus is being taught over two years.
In all the examination papers it is permissible to use an electronic calculator provided that it is not an algebraic or graphical calculator. Opportunities to practise using a calculator arise throughout the book, though in practice many questions will not require the use of a calculator and candidates should be able to use mental and written methods. Indeed certain questions may require evidence of a written method being used.
Note that because this book is written for the extended syllabus a number of core topics – basic arithmetic, measures, time, money, etc. – are not covered explicitly but are woven into the treatment of more advanced topics.
The support website contains extra exam practice material and presentations, one for each section of the book, that provide many more fully worked examples. All this material can be found online at www.oxfordsecondary.com/9780198424802
1About this book
About this book
When a calculation involves more than one operation it is important to do the operations in the correct order.1 Work out the Brackets first.2 Work out the Indices next.3 Work out the Divisions and Multiplications next.4 Work out the Additions and Subtractions last.
EXA
MPL
E Calculate 150 − 32 × (8 + 4) + 6 ÷ 2
150 − 32 × (8 + 4) + 6 ÷ 2= 150 − 32 × 12 + 6 ÷ 2= 150 − 9 × 12 + 6 ÷ 2= 150 − 108 + 3 = 45
brackets firstindices next, 32 means 3 × 3 = 9division and multiplication nextaddition and subtraction last
EXERCISE 1 .1
Work out: 1 2 + 3 × 5 2 8 ÷ 2 + 4 3 3 × 4 − 5 × 2 4 5 × 6 − 8 ÷ 2
5 7 − 2 × 3 + 5 6 10 − 2 × 3 7 6 + (3 × 5) − 2 8 10 + 32 × 4
9 (5 + 4) − 3 × 2 10 (5 × 4) − (3 × 2) 11 (4 × 3) × 22 12 5 × (4 − 3) × 2
13 5 × (16 − 3 × 2) 14 38 ÷ 2 − 4 × 3 15 56 − (23 + 4) 16 4 + (3 × 2)2
17 (4 × 3 + 2)2 18 (2 × 32) + 4 19 43 − 5 × 6 20 5 × (23 + 32)
EXERCISE 1 .2
Copy these and use brackets (where necessary) to make the statements true. 1 2 + 3 × 4 + 5 = 25 2 2 × 3 + 4 × 5 = 26
3 2 + 3 × 4 + 5 = 29 4 2 + 3 × 42 = 80
5 2 × 3 + 4 × 5 = 46 6 5 + 4 × 3 − 2 = 15
7 2 × 3 + 4 × 5 = 50 8 2 × 3 + 4 × 5 = 70
9 2 + 3 × 4 + 5 = 45 10 2 + 3 × 42 = 50
Memory aidB I D M A S• Brackets • Indices• Division• Multiplication• Addition• Subtraction
Order of operationsTHIS SECTION WILL SHOW YOU HOW TO• Perform operations in the correct order
2 UNIT 1
Directed numbersTHIS SECTION WILL SHOW YOU HOW TO• Perform the four rules on directed numbers
The positive and negative whole numbers are called integers.They can be shown on a number line. The number line can be used in practical situations.To find the difference between a temperature of 5 °C and a temperature of −3 °C, you find the gap between these two numbers on the number line. The difference is 8 °C.
Adding and subtracting directed numbers
The rules for adding and subtracting directed numbers are:
Change −2 + +5 to −2 + 5 = 3Change −2 + −5 to −2 − 5 = −7Change −2 − +5 to −2 − 5 = −7Change −2 − −5 to −2 + 5 = 3
EXA
MPL
E Work out a (−9) − (−3) b (+8) − (+15) c (29) + (−12)
a −9 − −3 = −9 + 3 = −6 change − − to +b +8 − +15 = +8 − 15 = −7 change − + to −c 29 + −12 = 29 − 12 = 17 change + − to −
EXERCISE 1 .3
Work out: 1 (−3) + (−5) 2 6 − (−4) 3 8 + (−10)
4 2 + (−5) 5 (−4) − (+2) 6 (−15) + (−3)
7 36 + (−8) 8 29 − (+1) 9 (−52) − (−38)
10 (−54) + (−3) 11 (−16) + (−2) 12 (−20) − (−20)
13 (−57) + (+5) 14 41 + (−16) 15 52 − (−3)
16 (−5) − (+10) 17 (−7) − (−14) 18 (−42) + (−5)
19 (−8) + (−2) + (−5) 20 (−6) − (+2) − (−3) 21 7 − (−2) + (−3)
22 (+9) − (−6) + (−6) 23 7 − (+9) + (−3) 24 46 − (−12) + (−5)
–1 –2 0
NEGATIVE NUMBERS POSITIVE NUMBERS
1 2–6 –5 –4 –3 6543
3Directed numbers
KEY WORDSpositive negative integer
Multiplying and dividing directed numbers
The rules for multiplying and dividing directed numbers are:
Multiplication Division+ × + = + + ÷ + = ++ × − = − + ÷ − = −− × + = − − ÷ + = −− × − = + − ÷ − = +
EXA
MPL
E Work out a (−6) ÷ (−2) b 5 × (−8) c (−4)3
a (−6) ÷ (−2) = 3
b 5 × (−8) = −40
c (−4)3 = −4 × −4 × −4 = 16 × −4 = −64
the two signs are the same so the answer is positive
the two signs are different so the answer is negative
first multiply −4 by −4then multiply by −4 again
EXERCISE 1 .4
Work out: 1 (−12) × (−5) 2 (−8) × (+4) 3 (+16) × (−2)
4 (−52) ÷ (−13) 5 (−55) ÷ (+5) 6 (−145) ÷ (−5)
7 (+20) ÷ (−2) 8 (−95) ÷ (−19) 9 (−11) × (−11)
10 (−3) × (−4) × (−5) 11 (−2) × (+8) × (−4) 12 (+6) × (−3) × (−7)
13 (−2) × (−5) × (+6) 14 (−9)2 15 (−15)2
16 (−5)3 17 (−60)3 18 (−4)3 × (−1)3
19 (−2)5 × (−10)2 20 (−1)13 21 (−1)15 × (−1)24
22 −−
63 23
− +−
( ) ( )10 315×
24 − −− +
( ) ( )( ) ( )
12 52 10
××
25 Check your answers to questions 1 to 18 using a calculator.
Find the missing numbers:
26 2
128 2
48× =−÷ −
( )( )
27 -( )5
103× = 28
÷− −( ) ( )
−32 6
1×
=
If the two signs are the same, the answer will be positive.If the two signs are different, the answer will be negative.
4 UNIT 1
UN
IT 1
UN
IT 1
Multiples, factors, primes, squares and cubesTHIS SECTION WILL SHOW YOU HOW TO• Identify and use factors, multiples, primes, squares and cubes
Factors
The whole numbers that divide exactly into 15 are called factors of 15. The factors of 15 are 1, 3, 5 and 15.
EXA
MPL
E List all the factors of 24.
24 = 1 × 2424 = 2 × 1224 = 3 × 824 = 4 × 6Factors of 24 = 1, 2, 3, 4, 6, 8, 12 and 24.
write 24 as the product of two factorsrepeat until all pairs have been found
EXA
MPL
E Find the highest common factor (HCF) of 20 and 36.
Factors of 20 = 1 , 2 , 4 , 5, 10, 20Factors of 36 = 1 , 2 , 3, 4 , 6, 9, 12, 18, 36Common factors of 20 and 36 are 1, 2, and 4.Highest common factor of 20 and 36 is 4.
list the factors of both 20 and 36
find the numbers that are in both listsselect the highest number
Multiples
The multiples of 6 are the numbers 6, 12, 18, 24, 30 …
EXA
MPL
E Find the lowest common multiple (LCM) of 12 and 9.
Multiples of 12 = 12, 24, 36 , 48, 60, 72 , 84 …
Multiples of 9 = 9, 18, 27, 36 , 45, 54, 63, 72 , 81 … Common multiples of 12 and 9 are 36, 72 …Lowest common multiple of 12 and 9 is 36.
list the multiples of 12 and 9
find the numbers that are in both listsselect the lowest number
5Multiples, factors, primes, squares and cubes
EXERCISE 1 .5
1 Write down all the factors of:a 10 b 15 c 9 d 17 e 60f 80 g 100 h 64 i 125 j 90
2 Find the common factors of:a 6 and 8 b 10 and 15 c 9 and 18d 16 and 20 e 20 and 25 f 12 and 30g 80 and 100 h 42 and 48 i 6, 12 and 42
3 Find the highest common factor (HCF) of:a 6 and 8 b 10 and 15 c 90 and 18d 36 and 45 e 23 and 46 f 20 and 24g 30 and 45 h 42 and 48 i 8, 32 and 44
4 List the first six multiples of each of the following numbers.a 10 b 6 c 9 d 18 e 25f 40 g 100 h 12 i 27 j 121
5 Find the lowest common multiple (LCM) of:a 6 and 8 b 5 and 15 c 6 and 9d 7 and 8 e 4 and 6 f 12 and 8g 14 and 21 h 11 and 5 i 8, 10 and 12
6 A piece of rope can be cut into an exact number of 6 m lengths. The rope could also be cut into an exact number of 8 m lengths. What is the shortest possible length of the rope?
7 A light flashes every 15 minutes. A second light flashes every 18 minutes. Both lights flash together at 2 a.m. What will be the time when they next flash together?
8 A bell rings every 20 seconds. A second bell rings every 25 seconds. A third bell rings every 30 seconds. They all ring together at 8 p.m. How long will it be before all three bells ring together again?
6 UNIT 1
UN
IT 1
Primes
A prime number is a number that has exactly two factors.5 is a prime number because it has exactly two factors (1 and 5)
EXA
MPL
E List the first ten prime numbers
The prime numbers are: 2, 3, 5, 7, 11, 13, 17, 19, 23 and 29
A prime factor is a factor that is also a prime number.
EXA
MPL
E List the prime factors of 30.
The factors of 30 are: 1, 2 , 3 , 5 , 6, 10, 15 and 30The prime factors of 30 are: 2, 3 and 5.
select the factors that are prime
Numbers can be written as the product of prime factors.For example 120 = 2 × 60 = 2 × 2 × 30 = 2 × 2 × 2 × 15 = 2 × 2 × 2 × 3 × 5 = 23 × 3 × 5The next example shows how a factor tree can be used.
EXA
MPL
E Write 84 as the product of prime factors.
84
2 42
2 21
3 7 84 = 2 × 2 × 3 × 7 = 22 × 3 × 7
Expressing numbers as the product of prime factors can help you to find highest common factors (HCF) and lowest common multiples (LCM).
EXA
MPL
E Find the HCF and the LCM of 270 and 420.
First write 270 and 420 as the product of prime factors.270 = 2 × 3 × 3 × 3 × 5 and 420 = 2 × 2 × 3 × 5 × 7 Write the prime factors on a diagram.
Prime factorsof 420
3 3 2 3 5 2 7
Prime factorsof 270
The HCF is the product of the numbers in the intersection = 2 × 3 × 5 = 30.The LCM is the product of all the numbers in the diagram = 3 × 3 × 2 × 3 × 5 × 2 × 7 = 3780.
7
UN
IT 1
Multiples, factors, primes, squares and cubes
EXERCISE 1 .6
1 Which of the following numbers are prime numbers? 11, 17, 21, 35, 47, 69, 72, 81.
2 Which of the following numbers are prime numbers? 3, 13, 23, 33, 43, 53, 63, 73.
3 Calculate the value of the following.a 2 × 5 × 5 b 2 × 3 × 11 c 3 × 3 × 3 × 7 d 2 × 5 × 7e 2 × 3 × 3 × 13 f 2 × 2 × 3 × 11 g 33 × 52 × 7 h 25 × 32 × 5 × 11
4 Write each of the numbers as the product of prime factors.a 10 b 150 c 81 d 60 e 74 f 100 g 98 h 250 i 1110 j 275 k 2004 l 2210
5 3, 7, 10, 15, 19, 21, 35a Which of these numbers are prime numbers?b Which of these numbers are multiples of 3?c Which of these numbers are multiples of 5? d Which of these numbers are factors of 30?e Which of these numbers are factors of 380?
6 List the prime numbers between 80 and 100.
7 Sanjit thinks that 713 is a prime number. Explain why he is wrong.
8 The number 12 can be written as the sum of two prime numbers. 12 = 5 + 7 Write each of the following numbers as the sum of two prime numbers.
a 10 b 14 c 25 d 49 e 30f 20 g 38 h 82 i 36 j 48
9 Find the HCF and LCM of:a 24 and 42 b 45 and 105 c 70 and 42 d 40 and 75
10 Find the HCF and LCM of:a 30, 36 and 42 b 28, 35 and 56 c 60, 90 and 210
8 UNIT 1
UN
IT 1
Square and cube numbers
1 × 1 = 1 2 × 2 = 4 3 × 3 = 9 4 × 4 = 16
The numbers 1, 4, 9 and 16 are called square numbers.The number 169 is also a square number because 13 × 13 = 16913 × 13 can be written as 132
1 × 1 × 1 = 1 2 × 2 × 2 = 8 3 × 3 × 3 = 27
The numbers 1, 8 and 27 are called cube numbers. The number 8000 is a cube number because 20 × 20 × 20 = 8000.20 × 20 × 20 can also be written as 203.
EXERCISE 1 .7
1 Which is biggest 23 or 32?
2 1, 5, 9, 20, 27, 56, 48, 49, 52, 64, 275, 289, 343, 436, 512.a Write down the numbers that are square numbers.b Write down the numbers that are cube numbers.
3 The number 64 is a square number because 8 × 8 =64. It is also a cube number because 4 × 4 × 4 = 64. Can you find another number (bigger than 1) that is both
a square and a cube number?
KEY WORDSfactor
highest common factor (HCF)
multiple lowest common multiple (LCM)
prime prime factor
product of prime factors square numbers cube numbers
9
UN
IT 1
Multiples, factors, primes, squares and cubes
The language of fractions
In the fraction 37 , the top part is called the numerator and the bottom part is
called the denominator.
The fraction 83 is called an improper fraction because the numerator is bigger than
the denominator.
The number 2 23
is called a mixed number because it is made up of a whole number and a fraction.To simplify a fraction you divide the numerator and denominator by a common factor.
÷ by 2
÷ by 2
68
34
=
EXERCISE 1 .8
Simplify:
1 6
12 2
3549
3 1824
4 6
15 5
80128 6
150175
7 3663
8 6075
9 4248
10 36
132 11
5160 12
84144
Change to mixed numbers:
13 85
14 73
15 157
16 2017
17 132
18 194
19 1712
20 4715
21 158
22 2221
23 175
24 309
Four rules for fractionsTHIS SECTION WILL SHOW YOU HOW TO• Use the language of fractions• Apply the four rules for fractions
10 UNIT 1
Adding and subtracting fractions
To add or subtract fractions a common denominator is needed as shown below.EX
AM
PLE Calculate a 2
34 + 1
25 b 3
15 − 1
23
a 234 + 1
25
= 21520 + 1
820
= 32320
= 43
20
b 315 − 1
23
= 33
15 − 11015
= 21815 − 1
1015 = 1
815
write both fractions with a common denominator of 20
write both fractions with a common denominator of 15
3 2 1 23
15
3
15
18
15= + =
EXERCISE 1 .9
Calculate:
1 112 + 2
13 2 3
14 + 2
15 3 5
16 + 2
37 4 3
23 + 3
45
5 156 + 2
34 6 2
56 + 1
25 7 2
38 + 1
45 8 5
23 + 9
79
9 345 − 1
12 10 2
58 − 2
13 11 6
47 − 3
29 12 4
78 − 2
35
13 578 − 2
35 14 2
25 − 1
56 15 6
16 − 2
34 16 7
25 − 3
47
17 −345 + 1
12 18 4
23 − −⎛
⎝⎜⎞⎠⎟
215 19 2
12 + 3
13 − 1
34 20
12 − 2
13 +
56
21 215 − 1
45 − 1
23 22 5 − 2 11
315
+⎛⎝⎜
⎞⎠⎟
23 Use a calculator to check your answers to questions 1 to 22.
11
UN
IT 1
Four rules for fractions
24 Omar has some money. He spends 15
of the money on a book, 37
of the money on a CD and he puts the rest of the money in a bank. What fraction of the money does he put in the bank?
25 Fatimah has 3 kg of flour. She uses 135 kg to make some bread
and 34 kg to make a cake. How much flour does she have left?
26 The sum of two fractions is 6 45
. One of the fractions is 4 910
. Find the other fraction.
27 The difference of two fractions is 4 27 . One of the fractions is 2 3
5.
Find the other fraction.
28 Find the fraction that is halfway between −12 and 1
3.
29 Arrange these fractions in order of size starting with the smallest:
a 35
23
1330
, , b 7
121118
59
, ,
c 45
34
710
, , d 56
89
1112
, ,
Multiplying and dividing fractions
EXA
MPL
E Calculate a 215
× 1 34
b 3 13
÷ 3 12
a 2 15
× 1 34
= 115
× 74
= 7720
= 31720
b 3 13
÷ 3 12
= 103
÷ 72
= 103
× 27
= 2021
change to improper fractions
multiply the numerators, multiply the denominators
change to a mixed number
change to improper fractions
dividing by 72
is the same as multiplying by 27
multiply the numerators, multiply the denominators
TOP TIPChange the fractions so they have the same common denominators.
12 UNIT 1
UN
IT 1
The reciprocal of a number
A number multiplied by its reciprocal is always equal to 1.
= 1
= 1number
×5 15
× reciprocal
To obtain the reciprocal of a number, you divide 1 by the number.The reciprocal of 5 is 1
5 and the reciprocal of
23 is
32 .
EXERCISE 1 .10
Calculate:
1 1 23
× 215
2 214 × 2
14 3 3
25 × 1
16 4 5
27 × 3
34
5 4 56
× 213 6 7 3
10 × 2
45 7 1
12 ÷ 2
13 8 3
34 ÷ 1
12
9 256 ÷ 1
23 10 3
18 ÷
45 11
59
÷ 112 12 2
45 ÷ 2
23
13 35
2⎛⎝⎜
⎞⎠⎟
14 2 12
2⎛⎝⎜
⎞⎠⎟
15 3
20
3⎛⎝⎜
⎞⎠⎟
16 113
3⎛⎝⎜
⎞⎠⎟
17 14
25
+ × 38 18 2 1
438
35
− ÷
19 Check your ansewrs to questions 1 to 18 using a calculator.
Find the missing numbers:
20 35
× = 1 21 × 23 = 1 22 ÷
37 = 5
8 23 × 21
5 = 5
24 Tom has six bottles of juice. Each bottle contains 58
of a litre. How many litres of juice does he have altogether?
25 Write down the reciprocal of each of these numbers.
a 3 b 7 c 12 d
18
e 35
f 67 g 2
13 h 1
34
TOP TIP
2 2 21
2
1
2
1
2
2⎛⎝⎜
⎞⎠⎟
means ×
KEY WORDSnumerator
denominator improper fraction
mixed number reciprocal
13
UN
IT 1
Four rules for fractions
Also available:9780198428473
Pemberton Mathematics for Cambridge IGCSE: Extended directly matches the latest Cambridge IGCSE Mathematics syllabus for first examination from 2020. Taking an active learning approach, this title provides full coverage using carefully chosen examples and a large range of practice questions. With clear language and progression of content, it will support EAL students’ subject and language knowledge.
• Fully prepare for exams – comprehensive coverage of the course
• Develop advanced skills – differentiated practice extends performance
• Progress to the next stage – clear language support eases the transition to 16-18 study
Empowering every learner to succeed and progress
Complete Cambridge syllabus match
Comprehensive exam preparation
Reviewed by subject specialists
Embedded critical thinking skills
Progression to the next educational stage
AuthorSue Pemberton
Support learning with additional content on the accompanying support site:www.oxfordsecondary.com/9780198424802
Extended
Pemberton
Mathematicsfor Cambridge IGCSE®
Third Edition
9 780198 424802
ISBN 978-0-19-842480-2
1How to get in contact:web www.oxfordsecondary.com/cambridgeemail [email protected] +44 (0)1536 452620 fax +44 (0)1865 313472