revise pearson edexcel international gcse (9-1 ......international gcse (9-1) mathematics a revision...
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Revise Pearson Edexcel International GCSE (9-1)
Mathematics A Revision Guide
Sample
NUMBER1 Factors and primes
2 Indices 1
3 Indices 2
4 Calculator skills 1
5 Fractions
6 Decimals
7 Recurring decimals
8 Surds 1
9 Calculator skills 2
10 Ratio
11 Proportion
12 Percentage change
13 Reverse percentages
14 Repeated percentage change
15 Upper and lower bounds
16 Standard form
17 Problem-solving practice 1
18 Problem-solving practice 2
ALGEBRA19 Algebraic expressions
20 Expanding brackets
21 Factorising
22 Linear equations 1
23 Linear equations 2
24 Formulae
25 Arithmetic sequences
26 Straight-line graphs 1
27 Straight-line graphs 2
28 Parallel and perpendicular
29 Quadratic graphs
30 Cubic and reciprocal graphs
31 Rates of change
32 Quadratic equations
33 The quadratic formula
34 Completing the square
35 Simultaneous equations 1
36 Simultaneous equations 2
37 Inequalities
38 Trigonometric graphs
39 Transforming graphs 1
40 Transforming graphs 2
41 Inequalities on graphs
42 Sketching graphs
43 Using quadratic graphs
44 Turning points
45 Quadratic inequalities
46 Gradients of curves
47 Proportion and graphs
48 Proportionality formulae
49 Harder relationships
50 Rearranging formulae
51 Sequences and series
52 Algebraic fractions
53 Quadratics and fractions
54 Surds 2
55 Functions
56 Composite functions
57 Inverse functions
58 Differentiation
59 Gradients and calculus
60 Turning points and calculus
61 Kinematics
62 Algebraic proof
63 Problem-solving practice 1
64 Problem-solving practice 2
GEOMETRY AND MEASURES65 Speed
66 Density
67 Other compound measures
68 Angle properties
69 Solving angle problems
70 Angles in polygons
71 Perimeter and area
72 Units of area and volume
73 Prisms
74 Circles and cylinders
75 Sectors of circles
76 Pythagoras’ theorem
77 Trigonometry 1
78 Trigonometry 2
79 Volumes of 3D shapes
80 Surface area
81 Translations, refl ections and rotations
82 Enlargements
83 Combining transformations
84 Bearings
85 Scale drawings and maps
86 Constructions
87 Similar shapes 1
88 Similar shapes 2
89 The sine rule
90 The cosine rule
91 Triangles and segments
92 Pythagoras in 3D
93 Trigonometry in 3D
94 Circle facts
95 Intersecting chords
96 Circle theorems
97 Vectors
98 Vector proof
99 Problem-solving practice 1
100 Problem-solving practice 2
PROBABILITY AND STATISTICS
101 Mean, median and mode
102 Frequency table averages
103 Interquartile range
104 Cumulative frequency
105 Histograms
106 Probability
107 Relative frequency
108 Set notation
109 Venn diagrams
110 Probability and sets
111 Conditional probability
112 Tree diagrams
113 Problem-solving practice 1
114 Problem-solving practice 2
115 FORMULAE SHEET
116 ANSWERS
A small bit of small printEdexcel publishes Sample Assessment Material and the Specifi cation on its website. This is the offi cial content and this book should be used in conjunction with it. The questions in Now try this have been written to help you practise every topic in the book. Remember: the real exam questions may not look like this.
Contents
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SAMPLE
NUMBERHad a look Nearly there Nailed it!
1
Factors and primesThe factors of a number are any numbers that divide into it exactly. A prime number has exactly two factors. The prime numbers are 2, 3, 5, 7, 11, 13, 17, 19 and so on.
The highest common factor (HCF) of two numbers is the highest number that is a factor of both numbers.
84 � 2 � 2 � 3 � 7 � 22 � 3 � 7
Remember to put in the multiplication signs.This is called a product of prime factors.
Prime factorsIf a number is a factor of another number and it is a prime number then it is called a prime factor. You use a factor tree to fi nd prime factors.
84
422
76
3 2
Remember to circle the prime factors as you go along. The order doesn’t matter.
The lowest common multiple (LCM) of two numbers is the lowest number that is a multiple of both numbers.
To fi nd the HCF, circle all the prime numbers which are common to both products of primefactors. 2 appears twice in both products so you have to circle it twice. Multiply the circlednumbers together to fi nd the HCF.
Draw a factor tree. Continue until every branch ends with a prime number. This question asks you to write your answer inindex form. This means you need to use powers to say how many times each primenumber occurs in the product.
Check it!22 � 33 � 4 � 27 � 108 ✓
To fi nd the LCM multiply the HCF by each unshared prime from part (b).
(a) Write 108 as the product of itsprime factors. Give your answerin index form. (3 marks)
108
542
96
32 33
108 � 2 � 2 � 3 � 3 � 3 � 22 � 33
(b) Work out the highest common factor(HCF) of 108 and 24. (2 marks)
108 � 2 � 2 � 3 � 3 � 324 � 2 � 2 � 2 � 3HCF is 2 � 2 � 3 � 12
(c) Work out the lowest common multiple(LCM) of 108 and 24. (2 marks)
LCM � 12 � 3 � 3 � 2 � 216
2 X � 2 � 35 � 72 Y � 32 � 5 � 7
(a) Find the highest common factor(HCF) of X and Y. (2 marks)
(b) Find the lowest common multiple(LCM) of X and Y. (2 marks)
1 (a) Express 980 as a product of its prime factors. (3 marks)
(b) Find the highest common factor (HCF) of980 and 56. (2 marks)
You can use numbers given in index form directly:HCF: Choose the lowest power of each primeLCM: Choose the highest power of each prime.
M01_EDHM_RG_GCSE_8090_001-010.indd 1 12/7/18 12:28 PM
SAMPLE
Had a look Nearly there Nailed it! ALGEBRA
19
Algebraic expressionsYou need to be able to work with algebraic expressions confi dently. For a reminder about using the index laws with numbers have a look at pages 2 and 3.
You can use the index laws to simplify algebraic expressions.
a m � a n � a m + n
x 4 � x 3 � x 4 � 3 � x 7
a m ___ a n � a m � n
m 8 ÷ m 2 � m 8 − 2 � m6
(a m)n � a mn
(n 2)4 � n 2 � 4 � n 8
Algebraic expressions may also contain negative and fractional indices.
a�m � 1 ___ am
(c 2)−3 � c 2 � −3 � c −6 � 1 ___ c6
a 1 _ n � n √
__a
(8p3 ) 1 __ 3 � (8 )
1 __ 3 � (p 3 ) 1 __3
� 3 √ __ 8 � p 3 � 1 __
3
� 2p
You can square or cube a whole expression.
(4x 3y)2 � (4)2 � (x 3)2 � (y)2 � 16x 6y 2
Remember that if a letter appears on its own then it has the power 1.
16 � (4)2
(x 3)2 � x 3 � 2 � x 6
You need to square everything inside the brackets.
You can use the index lawsindex lawssimplify algebraic
1 2 3
One at a timeWhen you are multiplying expressions:1. Multiply any number parts fi rst.2. Add the powers of each letter to
work out the new power.6p 2q � 3p 3q 2 � 18p 5q 3
6 � 3 � 18p 2 � p 3 � p 2 � 3 � p 5
q � q 2 � q 1 � 2 � q 3
When you are dividing expressions:1. Divide any number parts fi rst.2. Subtract the powers of each letter to
work out the new power.
12a 5b 3 _______ 3a 2b 2 � 4a 3b
12 � 3 � 4b 3 � b 2 � b 3 � 2 � b
a 5 � a 2 � a 5 � 2 � a 3
(a) This is four lots of m2, so you write itas 4 x m2 or 4m2
(b) Use (a m)n � a mn
(c) Start by simplifying the top part of thefraction. Do the number part fi rst then the powers. Use a m � a n � a m � n
Next divide the expressions. Divide the number part, then divide the
indices using a m ___ a n � a m � n
Simplify fully
(a) m2 + m2 + m2 + m2 (1 mark)4m 2
(b) (x3)3 (1 mark)x 9
(c) 4y2 � 3y7________
6y (2 marks)
4y 2 � 3y 7
___________ 6y � 12y 9
_____ 6y � 2y 8
1 Simplify (h2)6 (1 mark)
2 Simplify fully(a) (2a5 b)4 (2 marks)(b) 5x 4y 2 � 3x 3y7 (2 marks)(c) 18d 8g10 � 6d 2g5 (2 marks)
Apply the power outside thebrackets to everything inside thebrackets.
3 (a) Simplify (16p10 ) 1 _ 2 (2 marks)
(b) Simplify (64x9y2 )− 1 _ 3 (2 marks)
(2 marks)
Worked
solution
video
Aiminghigher
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SAMPLE
Had a look Nearly there Nailed it!GEOMETRY & MEASURES
65
Speed
UnitsThe most common units of speed are:• metres per second: m / s• kilometres per hour: km / h
• miles per hour: mph.To convert between measures of speed you need to convert one unit fi rst then the other. Write the new units at each step of your working. To convert 72 km/h into m/s:72 km/h → 72 � 1000 � 72 000 m/h72 000 m/h → 72 000 � 3600 � 20 m/s1 hour � 60 � 60 � 3600 seconds
Minutes and hoursFor questions on speed, you need to be able to convert between minutes and hours.Remember there are 60 minutes in 1 hour.To convert from minutes to hours you divide by 60.24 minutes � 0.4 hours 24 ___ 60 � 2 __ 5 � 0.4
To convert from hours to minutes you multiply by 60.0.2 hours � 12 minutes 3.2 � 60 � 1923.2 hours � 3 hours 12 minutes
This is the formula triangle for speed.
S T
D
Average speed � total distance travelled ______________________ total time taken
Time � distance ______________ average speed
Distance � average speed � time
DistanceAverage speed Time
Using a formula triangleCover up the quantity you want to fi nd with your fi nger.
S T
D
T � D __ S S � D __ T D � S � T
The position of the other two quantities tells you the formula.
Speed checklistDraw formula triangle. Make sure units match. Give units with answer.
The speed of light in a vacuum is approximately 1.08 × 109 km/h.
Light from the Sun takes approximately 8 minutes and 15 seconds to travel to Earth.
Estimate the distance from the Earth to the Sun. (3 marks)
DS T
8 mins 15 secs = 8.25 mins = 8.25 _____ 60 = 0.1375 hours
D = S × T= 1.08 × 109 × 0.1375= 1.485 × 108 km
Rosa lives in Durham and works in Newcastle. She takes the train to work every day.
Last Tuesday her train journey to work took 12 minutes, at an average speed of 108 km/h.
Her journey home from work took 15 minutes.
Calculate Rosa’s average speed on her journey home. (3 marks)
Be careful with the units. You need to convert 12 minutes and 15 minutes into hours before doing your calculations.
If you’re answering questions involving speed, distance and time you must always make sure that the units match. Speed is given in km/h here, so convert the time into hours before calculating.
LEARN IT!
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SAMPLE
Had a look Nearly there Nailed it!PROBABILITY & STATISTICS
101
Mean, median and modeYou can analyse data by calculating statistics like the mean, median and mode.
Mean Median ModeAdd up all the
values
Divide by thetotal number of
values
Do not roundyour answer
More thanone value
with highestfrequency
All valueshave samefrequency
Lookfor the most
commonvalueOne value
with highestfrequency
This value isthe mode
These values areall modes
There is nomode
Evennumber
of values
Write thevalues in order ofsize, smallest first
Count thenumber of
valuesOddnumber
of values
The median isthe middle value
The median ishalf-way between
the two middle values
Add up all thevalues
Divide by thetotal number of
values
Do not roundyour answer
More thanone value
with highestfrequency
All valueshave samefrequency
Lookfor the most
commonvalueOne value
with highestfrequency
This value isthe mode
These values areall modes
There is nomode
Evennumber
of values
Write thevalues in order ofsize, smallest first
Count thenumber of
valuesOddnumber
of values
The median isthe middle value
The median ishalf-way between
the two middle values
Add up all thevalues
Divide by thetotal number of
values
Do not roundyour answer
More thanone value
with highestfrequency
All valueshave samefrequency
Lookfor the most
commonvalueOne value
with highestfrequency
This value isthe mode
These values areall modes
There is nomode
Evennumber
of values
Write thevalues in order ofsize, smallest first
Count thenumber of
valuesOddnumber
of values
The median isthe middle value
The median ishalf-way between
the two middle values
Which average works best?
Mean Uses all the data Affected by
extreme valuesMedian Not affected by
extreme valuesMay not be one of the values
Mode Suitable for data that can be described in words
Not always near the middle of the data
You can work out the sum of the 6 remaining
cards using this formula:
Sum of values � mean � number of values
Subtract this sum from the sum of all 8
cards. This tells you the sum of the 2 cards
Kayla removed. The removed cards were
either 5 and 7 or 8 and 4.
Check it!Work out the mean of the remaining 6 cards.
Kayla has eight numbered cards.
1 2 3 4 5 6 7 8She removes two cards. The mean value of the remaining cards is 4.Which two cards could Kayla have removed? Give one possible answer. (4 marks)
6 � 4 � 241 � 2 � 3 � 4 � 5 � 6 � 7 � 8 � 3636 � 24 � 12The removed cards add up to 12 so Kayla could have removed 7 and 5Check:
1 � 2 � 3 � 4 � 6 � 8 _______________________ 6 � 4 ✓
101
Takeshi scored these marks out of 20 in six maths tests.
11 9 5 13 15 12
How many marks must he score in the next test so that his new mean mark and his new median mark are the same as each other? (3 marks)
Make sure you check your answer by
calculating the new mean and median.
Remember that the median is not
affected by extreme values.
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SAMPLE