Percentages 2 - Arkleston Primary School

Park Mains HS
Numeracy Booklet
A Guide for pupils, parents and
teachers of all subjects as to how the
various Numeracy Outcomes are
approached within the School
Introduction
This is the 2nd Edition of the Park Mains Numeracy information booklet. Its aim
is to show how key numeracy topics are taught within the Math’s Department in
the hope that it will lead to a more consistent approach within school and at
home. Ultimately we hope that this will help pupils progress and raise their
attainment in mathematics.
At the end of the booklet is an outline of when we expect to teach these
topics within the Math’s department. Note that is it is possible that another
department may introduce a topic for the first time at High School. This
booklet has also been created to help support pupils when this happens.
We hope you find this guide useful .
We would like to thank James Gillespie’s High School, Edinburgh,
Gryffe High School, Renfrewshire and colleagues within Park Mains
High school and others for allowing us to use their valuable material
to help in the compilation of this guide.
2
Table of Contents
Topic
Page Number
Addition: MNU 3-03a
4
Subtraction: MNU 3-03a
5
Multiplication: MNU 3-03a
6
Division: MNU 3-03a
8
Units of Measure: MNU 3-11a
9
Order of Calculations (BODMAS): MNU 3-03b
10
Order of Calculations (BIDMAS) : MNU 3-03b
11
Evaluating Formulae: MTH 3-14a
12
Solving Equations: MTH 3-15a
13
Estimation – Rounding: MNU 3-01a
16
Estimation – Calculations: MNU 3-03a
17
Time: MNU 3-10a
18
Scientific Notation
20
Fractions: MTH 3-07b
21
Percentages: MNU 3-07a
24
Ratio: MNU 3-08a
29
Proportion: MNU 3-08a
32
Information Handling – Tables: MTH 3-21a
33
Information Handling - Bar Graphs: MTH 3-21a
34
Information Handling - Line Graphs: MTH 3-21a
35
Information Handling - Scatter Graphs: MTH 3-21a
36
Information Handling - Pie Charts: MTH 3-21a
37
Information Handling – Averages: MTH 3-20b
39
Angles: MTH 3-17a
40
Co-ordinates: MTH 3-18a
41
Pythagoras: MTH 4-16a
42
Mathematical Dictionary
43
S1 / S2 Course Outline
45
Useful Websites
46
3
Addition
MNU 3-03a: I can use a variety of methods to solve number problems in familiar
contexts, clearly communicating my processes and solutions.
Mental strategies
There are a number of useful mental strategies
for addition. Some examples are given below.
Example
Calculate 54 + 27
Method 1
Add tens, then add units, then add together
50 + 20 = 70
Method 2
4 + 7 = 11
Split up number to be added into tens and units and add
separately.
54 + 20 = 74
Method 3
70 + 11 = 81
74 + 7 = 81
Round up to nearest 10, then subtract
54 + 30 = 84
84 - 3 = 81
but 30 is 3 too much so subtract 3;
Written Method
When adding numbers, ensure that the numbers are lined up according
to place value. Start at right hand side, write down units, carry tens.
Note, carrying 10s, 100s etc will be done on the top of the sum line.
Example
Add 3032 and 589
3032
+589
1
1
2 + 9 = 11
3032
+589
1 1
21
3032
+589
1 1
621
3+8+1=12
0+5+1=6
4
3032
+589
1 1
3621
3+0=3
Subtraction
MNU 3-03a: I can use a variety of methods to solve number problems in familiar
contexts, clearly communicating my processes and solutions.
We use decomposition as a written method for
subtraction (see below). Alternative methods may be
used for mental calculations.
Mental Strategies
Example
Calculate 93 - 56
Method 1
Count on
Count on from 56 until you reach 93. This can be done in several ways
e.g.
4
56
30
60
70
Method 2
3
80
90
93
Break up the number being subtracted
e.g. subtract 50, then subtract 6
6
37
= 37
93 - 50 = 43
43 - 6 = 37
50
43
93
Start
Written Method
Example 1
4590 – 386
8 1
4
-
5
3
9
8
0
6
4
2
0
4
Example 2
We do not
“borrow and
pay back”.
Subtract 69.2 from 1459.7
1
-
43 15
6
9
9
.
.
7
2
1
3
0
.
5
9
Note : When adding or subtracting with
decimals, the decimal point always stays in line
5
Multiplication 1
MNU 3-03a: I can use a variety of methods to solve number problems in familiar
contexts, clearly communicating my processes and solutions.
It is essential that you know all of the multiplication
tables from 1 to 10. These are shown in the tables
square below. We also recommend that pupils in S1 and
S2 learn multiplication tables up to 12.
x
1
2
3
4
5
6
7
8
9
10
11
12
1
2
1
2
3
4
5
6
7
8
9
10
11
12
2
4
6
8
10
12
14
16
18
20
22
24
3
4
5
3
6
9
12
15
18
21
24
27
30
33
36
4
8
12
16
20
24
28
32
36
40
44
48
5
10
15
20
25
30
35
40
45
50
55
60
6
7
8
6
12
18
24
30
36
42
48
54
60
66
72
7
14
21
28
35
42
49
56
63
70
77
84
8
16
24
32
40
48
56
64
72
80
88
96
9
10
11
9
18
27
36
45
54
63
72
81
90
99
108
10
20
30
40
50
60
70
80
90
100
110
120
11
22
33
44
55
66
77
88
99
110
121
132
12 12 24 36 48
Mental Strategies
60
72
84
96
108
120
132
144
Example
Find 39 x 6
Method 1
Find 30 x6 = 180
Find 9 x 6 = 54
Then add your two answers, 180 + 54 = 234
Method 2 Find 40 x 6 = 240
40 is 1 too many so take away 6x1, 240 – 6 = 234
Written Method
Again, numbers should be lined up according to place value and carrying
10s etc will be done on top of the sum line.
Example
342 x 9
3
x
4
1
2
9
8
3
x
4
3
2
9
8
1
7
6
3
x
3
4
3
0
2
1 9
7
8
Multiplication 2
MNU 3-03a: I can use a variety of methods to solve number problems in familiar
contexts, clearly communicating my processes and solutions.
Multiplying by multiples of 10, 100 and 1000
To multiply by 10 move every digit one place to the left.
To multiply by 100 move every digit two places to the left.
To multiply by 1000 move every digit three places to the
left.
Example 1 (a) Multiply 354 by 10
Th
H
T
3
3
5
U
5
4
(b) Multiply 50.6 by 100
Th
H
T
4
0
5
354 x 10 = 3540
0
U
t
5
0
6
6
0
0
50.6 x 100 = 5060
(c) 35 x 30
(d) 436 x 600
To multiply by 30,
multiply by 3,
then by 10.
To multiply by
600, multiply by 6,
then by 100.
35 x 3 = 105
105 x 10 = 1050
436 x 6
= 2616
2616 x 100 = 261600
so 35 x 30 = 1050
so 436 x 600 = 261600
We may also use these rules for multiplying
decimal numbers.
Example 2
(a) 2.36 x 20
(b) 38.4 x 50
2.36 x 2 = 4.72
4.72 x 10 = 47.2
38.4 x 5 = 192.0
192.0x 10 = 1920
so 2.36 x 20 = 47.2
so 38.4 x 50 = 1920
7
Division
MNU 3-03a: I can use a variety of methods to solve number problems in familiar
contexts, clearly communicating my processes and solutions.
Dividing by multiples of 10, 100 and 1000
To divide by 10, move every digit one place to the right
To divide by 100, move every digit two places to the right
To divide by 1000, move every digit three places to the
right
Example
Th
H
3
(a) Divide 354 by 10
T
5
U
4
.
t
3
5
.
4
(b) Divide 50.6 by 100
H
T
5
U
0
.
.
t
6
h
th
0
.
5
0
6
Dividing by a single digit
Written Method
Example 1
There are 192 pupils in first year, shared equally between
8 classes. How many pupils are in each class?
24
8 1 932
There are 24 pupils in each class
Example 2
Divide 4.74 by 3
When dividing a decimal
number by a whole number,
the decimal points must stay
in line.
1·58
3 4 · 1724
Example 3
A jug contains 2.2 litres of juice. If it is poured evenly
into 8 glasses, how much juice is in each glass?
0 · 275
8 2 · 226040
If you have a remainder at
the end of a calculation, add
“trailing zeros” onto the end
of the decimal and continue
with the calculation.
Trailing zero
Each glass contains
0.275 litres
8
Units of Measure
MNU 3-11a: I can solve practical problems by applying my knowledge of measure,
choosing the appropriate units and degree of accuracy for the task and using a
formula to calculate area or volume when required.
Distances / Lengths
Weights
kilograms
( kg )
kilometres
(km)
x 1000
÷ 1000
metres (m)
x 100
grams ( g )
x 1000
÷ 100
centimetres
(cm)
x 10
÷ 1000
x 1000
÷ 1000
milligrams
(mg)
÷ 10
millimetres
(mm)
Volume
litres (l)
x 1000
÷ 1000
millilitres
( ml )
Ensure you choose the right units for your calculations.
Perimeter is defined as the length round the outside of a shape.
Area is defined as the amount of flat surface space a shape takes up.
This is a two dimensional measurement so units need to be eg cm 2 or
m2 . For example, the area of a rectangle is given by the formula,
Area = length x breadth
Volume is defined as the amount of three dimensional space a 3D
object takes up. Note that 1cm 3 = 1ml
9
Order of Calculation (BODMAS)
MNU 3-03b: I can continue to recall number facts quickly and use them accurately
when making calculations.
Consider this: What is the answer to 2 + 5 x 8 ?
Is it 7 x 8 = 56
or
2 + 40 = 42 ?
The correct answer is 42.
Calculations which have more than one operation need to
be done in a particular order. The order can be
remembered by using the mnemonic BODMAS
The BODMAS rule tells us which operations should be done first.
BODMAS represents:
(B)rackets
(O)f
(D)ivide
(M)ultiply
(A)dd
(S)ubract
Scientific calculators use this rule; some basic calculators may not, so
take care in their use.
Example 1
15 – 12 6
= 15 – 2
=
13
BODMAS tells us to divide first
Example 2
(9 + 5) x 6
= 14
x6
=
84
BODMAS tells us to work out the
brackets first
Example 3
18 + 6 (5-2)
= 18 + 6
3
= 18 + 2
=
20
Brackets first
Then divide
Now add
10
Order of Calculation (BIDMAS)
MNU 3-03b: I can continue to recall number facts quickly and use them accurately
when making calculations.
Calculations which have more than one operation need to
be done in a particular order. The order can be
remembered by using the mnemonic BIDMAS
The BIDMAS rule tells us which operations should be done first.
This is very similar to BODMAS rule on Page 9.
(B)rackets
(I)ndices
(D)ivide
(M)ultiply
(A)dd
(S)ubract
Be careful inputting into a scientific calculator, some calculators
require you to use brackets.
Example 1
5 + 32 × 2
= 5+9×2
= 5 + 18
= 23
BIDMAS tells us to work out 3 2 first
then multiply 9 × 2
then add 5 + 18
Example 2
1 × 42 × 2
8
= 1 × 16 × 2
8
= 1 × 32
8
BIDMAS tells us to work out the
indice first (42)
then multiply all three terms
= 4
Example 3
5+
4
2
=5+2
=7
=5+
16
2
Work out the square root first
then the division
then add
11
Note : Roots are
also indices eg
√4 = 4½
Evaluating Formulae
MTH 3-14a: I can collect like algebraic terms, simplify expressions and evaluate
using substitution.
To find the value of a variable in a formula, we
must substitute all of the given values into the
formula and then use BODMAS rules to work out
the answer.
Format for all formulae, should follow the 4 steps below.
Example 1
Use the formula P = 2L + 2B to evaluate P when L = 12 and B = 7.
P = 2L + 2B
P = 2 x 12 + 2 x 7
P = 24 + 14
P = 38
Step
Step
Step
Step
1: Write formula
2: Substitute numbers for letters
3: Start to evaluate (BODMAS)
4: Write answer
Example 2
Use the formula F = 32 + 1.8 C to evaluate F when C = 20
F = 32 + 1.8C
F = 32 + 1.8 x 20
F = 32 + 36
F = 68
Step 1: Write formula
Step 2: Substitute numbers for letters
Step 3: Start to evaluate (BODMAS)
Step 4: Write answer
Example 3
Use the formula I =
V
R
240
6=
R
240
Rx6=
xR
R
6R = 240
R = 40
I=
V
R
to evaluate R when V = 240 and I = 6
Note : We do not cross multiply in
S1 and S2. We deal with the
fraction by multiplying both sides by
what is on the denominator ( see
balancing equations )
12
Solving Equations 1
Method 1 : Cover Up
MTH 3-15a: Having discussed ways to express problems or statements using
mathematical language, I can construct, and use appropriate methods to solve, a range
of simple equations.
An equation is an expression which contains an equal sign.
For example:
x+4=6
x+5 = 7
x = 2
Y – 3 = 10
y = 13
x = 2 is the solution
17
2x
=
=
=
x
=
x
=
16
2
2x + 1
2x + 1
17
16
8
Cover up method
Cover up the letter
and look at the
equation to see
what number should
be under your
finger to make
both sides equal.
Other examples with the Cover up method
3m – 4 = 11
3m - 4 = 11
3m = 15
m =
15
3
m = 5
1
x+3 =
2
1
x+3 =
2
1
x =
2
6
6
1
x = 3, to find
2
one full x we multiply the 3
by 2 (the denominator) to
get 6
As we have
3
x = 2×3
x = 6
13
Solving Equations 2
Method 2 : Balancing
MTH 3-15a: Having discussed ways to express problems or statements using
mathematical language, I can construct, and use appropriate methods to solve, a range
of simple equations.
Example 1
2x
+
1
-1
=
5
-1
2x
=
4
2x
2
=
4
2
x
=
2
1
=
Example 2
2x
-
+1
Subtract 1 from both sides
Divide both sides by 2
5
+1
2x
=
6
2x
2
=
6
2
x
=
3
Example 3 :
Add 1 to both sides
Divide both sides by 2
Equations with fractions
x
3x
=
7
x =
7
x
3
“Remove” fraction by multiplying
both sides by denominator
x
=
21
14
Solving Equations 2
Method 2 : Balancing
MTH 3-15a: Having discussed ways to express problems or statements using mathematical
language, I can construct, and use appropriate methods to solve, a range of simple equations.
What happens if we have letters on both sides ?
Example 4
2x = x + 4
2x - x = x + 4 x = 4
x
We need to alter the
equation so that x only
appears on one side of the
equation.
Remove x from both
sides
Example 5
5x = 12 + x
5x - x = 12 + x - x
4x = 12
Subtract x from both sides
Divide both sides by 4
12
4
x =
x = 3
Example 6
7a + 16
7a + 16 – 7a
16
2a
=
=
=
=
a =
9a
9a – 7a
2a
16
16
2
a = 8
15
Estimation : Rounding
MNU 3-01a: I can round a number using an appropriate degree of accuracy, having
taken into account the context of the problem.
Numbers can be rounded to give an approximation.
2652
2600 2610
2620
2630
2640
2650
2660
2670
2680
2690
2700
2652 rounded to the nearest 10 is 2650.
2652 rounded to the nearest 100 is 2700. (2 figure accuracy)
2652 rounded to the nearest 1000 is 3000. (1 figure accuracy)
When rounding numbers which are exactly in the
middle, convention is to round up.
7865 rounded to the nearest 10 is 7870.
If the number ends in 4 or below -> Round Down
If the number ends in 5 or above -> Round Up
The same principle applies to rounding decimal numbers.
In general, to round a number, we must first identify the place value
to which we want to round. We must then look at the next digit to the
right (the “check digit”) - if it is 5 or more round up.
Example 1
Round 46 753 to the nearest thousand.
6 is the digit in the thousands column - the check digit (in the
hundreds column) is a 7, so round up.
46 753
= 47 000 to the nearest thousand
Example 2
Round 1.57359 to 2 decimal places
The second number after the decimal point is a 7 - the check digit
(the third number after the decimal point) is a 3, so round down.
1.57359
= 1.57 to 2 decimal places
16
Estimation : Calculation
MNU 3-03a: I can use a variety of methods to solve number problems in familiar
contexts, clearly communicating my processes and solutions.
We can use rounded numbers to give us an
approximate answer to a calculation. This allows
us to check that our answer is sensible.
Example 1
Tickets for a concert were sold over 4 days. The number of tickets
sold each day was recorded in the table below. How many tickets were
sold in total?
Monday
486
Tuesday
205
Wednesday Thursday
197
321
Estimate = 500 + 200 + 200 + 300 = 1200
Calculate:
486
205
197
+321
1209
Answer = 1209 tickets
Example 2
A bar of chocolate weighs 42g. There are 48 bars of chocolate in a
box. What is the total weight of chocolate in the box?
Estimate = 50 x 40 = 2000g
Calculate:
42
x48
336
1680
2016
8 x 42
40 X 42
Answer = 2016g
17
Time 1
MNU 3-10a: Using simple time periods, I can work out how long a journey will take,
the speed travelled at or distance covered, using my knowledge of the link between
time, speed and distance.
Time may be expressed in 12 or 24 hour notation.
12-hour clock
Time can be displayed on a clock face, or digital clock.
These clocks both show
fifteen minutes past five,
or quarter past five.
When writing times in 12 hour clock, we need to add a.m. or p.m. after
the time.
a.m. is used for times between midnight and 12 noon (morning)
p.m. is used for times between 12 noon and midnight (afternoon /
evening).
24-hour clock
In 24 hour clock, the hours are written as
numbers between 00 and 24. Midnight is
expressed as 00 00, or 24 00. After 12 noon, the
hours are numbered 13, 14, 15 … etc.
Examples
9.55 am
3.35 pm
12.20 am
02 16 hours
20 45 hours
18
09 55 hours
15 35 hours
00 20 hours
2.16 am
8.45 pm
Time 2
MNU 3-10a: Using simple time periods, I can work out how long a journey will take,
the speed travelled at or distance covered, using my knowledge of the link between
time, speed and distance.
It is essential to know the number of months, weeks
and days in a year, and the number of days in each
month.
Time Facts
In 1 year, there are:
365 days (366 in a leap year)
52 weeks
12 months
The number of days in each month can be remembered using the
rhyme:
“30 days hath September,
April, June and November,
All the rest have 31,
Except February alone,
Which has 28 days clear,
And 29 in each leap year.”
Calculation of Time duration.
When working out time difference, we always use the ‘Counting On’
Method. We do not use ‘subtraction’.
Set time out as a horizontal line, broken into minutes and/or hours, for
example, how long is it from 0755 to 1048 ?
Nearest hr
0755
5 mins
hours
0800
+
2hrs
remaining mins
1000
+
0948
48 mins = 2hrs 53 mins
Changing minutes into hours :
27 minutes = 27 ÷ 60 = 0.45 hours
This is particularly useful when doing time, distance, speed
calculations, as follows.
19
Time 3
MNU 3-10a: Using simple time periods, I can work out how long a journey will take,
the speed travelled at or distance covered, using my knowledge of the link between
time, speed and distance.
Distance, Speed and Time.
For any given journey, the distance travelled depends on the speed and
the time taken. If speed is constant, then the following formulae
apply:
Distance = Speed x Time
Speed =
Time =
Example
Distance
Time
Distance
Speed
or
or D = ST
or S =
T=
D
T
D
S
Calculate the speed of a train which travelled 450 km in
5 hours
D
S=
T
450
S=
5
S = 90 km/h
Scientific Notation ( Standard Form )
In Maths scientific notation is written in the form
n
where
and n is an integer
For large numbers, n is positive eg 379000 = 3.79 x 10 5
8.01 x 104 = 80100
For small numbers, n is negative eg 0.251 = 2.51 x 10 -1
6.34 x 10 -3 = 0.00634
20
Fractions 1
MTH 3-07b: By applying my knowledge of equivalent fractions and common multiples,
I can add and subtract commonly used fractions.
Understanding Fractions
Example
A necklace is made from black and white beads.
What fraction of the beads is black?
There are 3 black beads out of a total of 7, so
black.
3
of the beads are
7
Equivalent Fractions
Example
What fraction of the flag is shaded?
6 out of 12 squares are shaded. So
It could also be said that
6
of the flag is shaded.
12
1
the flag is shaded.
2
6
1
and
are equivalent fractions.
2
12
Examples of equivalent fractions
1
2
2
4
3
6
3
8
6
16
4
8
9
24
5
10
15
40
6
12
10
20
1
3
30
80
2
6
2
5
21
3
9
4
12
5
15
6
18
4
10
6
15
10
25
20
50
10
30
Fractions 2
MTH 3-07b: By applying my knowledge of equivalent fractions and common multiples,
I can add and subtract commonly used fractions.
Simplifying Fractions
The top of a fraction is called the numerator; the
bottom is called the denominator.
To simplify a fraction, divide the numerator and
denominator of the fraction by the same number.
Example 1
(a)
20
25
÷5
=
(b)
4
5
16
24
÷8
=
2
3
÷5
÷8
This can be done repeatedly until the numerator and denominator are
the smallest possible numbers - the fraction is then said to be in its
simplest form.
Example 2
Simplify
72
84
72
36
18
6
=
=
=
(simplest form)
84
42
21
7
Calculating Fractions of a Quantity
To find the fraction of a quantity, divide by the
denominator, then multiply by the numerator.
3
To find
divide by 5 then multiply the answer by 3
5
OR multiply by 3 first then divide the answer by 5
Example 1
Find
1
of £150
5
= £150 ÷ 5
= £30
1
of £150
5
Example 2
1
of 48
4
= 48 ÷ 4
= 12
“Divide by the bottom,
multiply by the top”
22
Find
3
of 48
4
3
of 48
4
= 3 x 12
= 36
so
Fractions 3
MTH 3-07b: By applying my knowledge of equivalent fractions and common multiples,
I can add and subtract commonly used fractions.
Adding and Subtracting Fractions
To add or subtract fractions, the denominators
must be equal. Use process for finding
equivalent fractions with the denominator as
the lowest common multiple.
Multiplying and Dividing Fractions
To multiply fractions,
multiply the two
numerators together
and the two
denominators together
To divide fractions,
invert the second
fraction and then
multiply
23
Percentages 1
MNU 3-07a: I can solve problems by carrying out calculations with a wide range of
fractions, decimal fractions and percentages, using my answers to make comparisons
and informed choices for real-life situations.
Percent means out of 100.
A percentage can be converted to an equivalent fraction
or decimal by dividing by 100.
Decimal
(d)
36% means
36%
36
100
36
100
a÷b
9
25
d × 100
0.36
Fraction
a
( )
b
p
100
Percentage
(p%)
Common Percentages
Some percentages are used very frequently. It is useful to know
these as fractions and decimals.
Percentage
1%
10%
20%
25%
331/3%
50%
662/3%
75%
Fraction
1
100
1
10
1
5
1
4
1
3
1
2
2
3
3
4
24
Decimal
0.01
0.1
0.2
0.25
0.333…
0.5
0.666…
0.75
Percentages 2
MNU 3-07a: I can solve problems by carrying out calculations with a wide range of
fractions, decimal fractions and percentages, using my answers to make comparisons
and informed choices for real-life situations.
There are many ways to calculate percentages of a
quantity. Some of the common ways are shown below.
Non- Calculator Methods
Method 1
Using Equivalent Fractions
Example
Find 25% of £640
25% of £640
=
1
of £640
4
= £640 ÷ 4 = £160
Method 2 Using 1%
In this method, first find 1% of the quantity (by dividing by 100), then
multiply to give the required value.
Example
Find 9% of 200g
1% of 200g =
1
of 200g = 200g ÷ 100 = 2g
100
so 9% of 200g = 9 x 2g = 18g
Method 3 Using 10%
This method is similar to the one above. First find 10% (by dividing by
10), then multiply to give the required value.
Example
Find 70% of £35
10% of £35 =
1
of £35 = £35 ÷ 10 = £3.50
10
so 70% of £35 = 7 x £3.50 = £24.50
25
Percentages 3
MNU 3-07a: I can solve problems by carrying out calculations with a wide range of
fractions, decimal fractions and percentages, using my answers to make comparisons
and informed choices for real-life situations.
Non- Calculator Methods (continued)
The previous 2 methods can be combined so as to calculate any
percentage.
Example
Find 23% of £15000
10% of £15000 = £1500 so 20% = £1500 x 2 = £3000
1% of £15000 = £150 so 3% = £150 x 3 = £450
23% of £15000 = £3000 + £450 = £3450
Finding VAT (without a calculator)
Value Added Tax (VAT) = 17.5%
To find VAT, firstly find 10%, then 5% (by halving 10%’s value) and
then 2.5% (by halving 5%’s value)
Example
Calculate the total price of a computer which costs £650
excluding VAT
10% of £650 = £65
5% of £650 = £32.50
2.5% of £650 = £16.25
(divide by 10)
(divide previous answer by 2)
(divide previous answer by 2)
so 17.5% of £650 = £65 + £32.50 + £16.25 = £113.75
Total price
= £650 + £113.75 = £763.75
26
Percentages 4
MNU 3-07a: I can solve problems by carrying out calculations with a wide range of
fractions, decimal fractions and percentages, using my answers to make comparisons
and informed choices for real-life situations.
Calculator Method
To find the percentage of a quantity using a calculator, change the
percentage to a decimal, then multiply.
Example 1
Find 23% of £15000
23% = 0.23 so 23% of £15000 = 0.23 x £15000 = £3450
We do not use the % button on calculators. The methods
taught in the mathematics department are all based on
converting percentages to decimals.
Example 2
House prices increased by 19% over a one year period.
What is the new value of a house which was valued at
£236000 at the start of the year?
19% =
19
= 0.19
100
so
Increase = 0.19 x £236000
= £44840
Value at end of year = original value + increase
= £236000 + £44840
= £280840
The new value of the house is £280840
27
Percentages 5
MNU 3-07a: I can solve problems by carrying out calculations with a wide range of
fractions, decimal fractions and percentages, using my answers to make comparisons
and informed choices for real-life situations.
Making a percentage
To make a percentage of a total, first make a fraction,
and then multiply by 100.
Example 1
There are 30 pupils in Class 3A3. 18 are girls.
What percentage of Class 3A3 are girls?
18
30
= 18
30 = 0.6 = 60%
60% of 3A3 are girls
Example 2
James scored 36 out of 44 his biology test. What is his
percentage mark?
36
Score =
= 36 44 = 0.81818…
44
= 81.818..% = 82% (rounded)
Example 3
In class 1X1, 14 pupils had brown hair, 6 pupils had blonde
hair, 3 had black hair and 2 had red hair. What
percentage of the pupils were blonde?
Total number of pupils = 14 + 6 + 3 + 2 = 25
6 out of 25 were blonde, so,
6
= 6 25 = 0.24 = 24%
25
24% were blonde.
28
Ratio 1
MNU 3-08a: I can show how quantities that are related can be increased or
decreased proportionally and apply this to solve problems in everyday contexts.
When quantities are to be mixed together, the
ratio, or proportion of each quantity is often
given. The ratio can be used to calculate the
amount of each quantity, or to share a total into
parts.
Writing Ratios
Example 1
To make a fruit drink, 4 parts water is mixed
with 1 part of cordial.
The ratio of water to cordial is 4:1
(said “4 to 1”)
The ratio of cordial to water is 1:4.
Order is important when writing ratios.
Example 2
In a bag of balloons, there are 5 red, 7 blue
and 8 green balloons.
The ratio of red : blue : green is
5:7:8
Simplifying Ratios
Ratios can be simplified in much the same way as fractions.
Example 1
Purple paint can be made by mixing 10 tins of blue paint with 6 tins of
red. The ratio of blue to red can be written as 10 : 6
It can also be written as 5 : 3, as it is possible to split up the tins into
2 groups, each containing 5 tins of blue and 3 tins of red.
B B B
B B R R R
B B B
B B R R
R
Blue : Red = 10 : 6
= 5 :3
29
To simplify a ratio,
divide each figure in
the ratio by a
common factor.
Ratio 2
MNU 3-08a: I can show how quantities that are related can be increased or
decreased proportionally and apply this to solve problems in everyday contexts.
Simplifying Ratios (continued)
Example 2
Simplify each ratio:
(a) 4:6
(b) 24:36
(a) 4:6
= 2:3
(b) 24:36
= 2:3
Divide each
figure by 2
(c) 6:3:12
Divide each
figure by 12
(c) 6:3:12
= 2:1:4
Divide each
figure by 3
Example 3
Concrete is made by mixing 20 kg of sand with 4 kg cement. Write
the ratio of sand : cement in its simplest form
Sand : Cement = 20 : 4
= 5:1
Using ratios
The ratio of fruit to nuts in a chocolate bar is 3 : 2. If a bar contains
15g of fruit, what weight of nuts will it contain?
Fruit
3
Nuts
2
x5
x5
15
10
So the chocolate bar will contain 10g of nuts.
30
Ratio 3
MNU 3-08a: I can show how quantities that are related can be increased or
decreased proportionally and apply this to solve problems in everyday contexts.
Sharing in a given ratio
Example
Lauren and Sean earn money by washing cars. By the end of the day
they have made £90. As Lauren did more of the work, they decide to
share the profits in the ratio 3:2. How much money did each receive?
Step 1
Add up the numbers to find the total number of parts
3+2=5
Step 2
Divide the total by this number to find the value of each
part
90 ÷ 5 = £18
Step 3
Multiply each figure by the value of each part
3 x £18 = £54
2 x £18 = £36
Step 4
Check that the total is correct
£54 + £36 = £90
So Lauren received £54 and Sean received £36.
31
Proportion
MNU 3-08a: I can show how quantities that are related can be increased or
decreased proportionally and apply this to solve problems in everyday contexts.
Two quantities are said to be in direct proportion
if when one doubles the other doubles.
We can use proportion to solve problems.
It is often useful to make a table when solving problems involving
proportion.
Example 1
A car factory produces 1500 cars in 30 days. How many cars would
they produce in 90 days?
Days
30
Cars
1500
x3
x3
90
4500
The factory would produce 4500 cars in 90 days.
Example 2
5 adult tickets for the cinema cost £27.50. How much would 8 tickets
cost?
Find the cost
of 1 ticket
Tickets
5
1
8
Cost
£27.50
£5.50
£44.00
The cost of 8 tickets is £44
32
Working:
£5.50
5 £27.50
£5.50
4x 8
£44.00
Information Handling : Tables
MTH 3-21a: I can display data in a clear way using a suitable scale, by choosing
appropriately from an extended range of tables, charts, diagrams and graphs, making
effective use of technology.
It is sometimes useful to display information in
graphs, charts or tables.
Example 1
Barcelona
Edinburgh
The table below shows the average maximum
temperatures (in degrees Celsius) in Barcelona and
Edinburgh.
J F M A M J J A S O N D
13 14 15 17 20 24 27 27 25 21 16 14
6 6 8 11 14 17 18 18 16 13 8 6
The average temperature in June in Barcelona is 24 C
Frequency Tables are used to present information. Often data
is grouped in intervals.
Example 2
Homework marks for Class 4B
27 30 23 24 22 35 24 33 38 43 18 29 28 28 27
33 36 30 43 50 30 25 26 37 35 20 22 24 31 48
Mark
16 - 20
21 - 25
26 - 30
31 - 35
36 - 40
41 - 45
46 - 50
Tally
||
|||| ||
|||| ||||
||||
|||
||
||
Frequency
2
7
9
5
3
2
2
Each mark is recorded in the table by a tally mark.
Tally marks are grouped in 5’s to make them easier to read and
count.
33
Information Handling : Bar Graphs and Histograms
MTH 3-21a: I can display data in a clear way using a suitable scale, by choosing appropriately from
an extended range of tables, charts, diagrams and graphs, making effective use of technology.
Bar graphs and histograms are often used to
display data. The horizontal axis should show the
categories or class intervals, and the vertical axis
the frequency. All graphs should have a title, and
each axis must be labelled.
Example 1 This histogram shows the homework marks for Class 4B ( from
previous page ).
Class 4B Homework Marks
10
9
Number of pupils
8
7
6
5
4
3
2
1
0
16 - 20
21 - 25
26 - 30
31 - 35
36 - 40
41 - 45
46 - 50
Mark
Notice that the histogram is used for class intervals (it must remain in this
order) and has no gaps.
Example 2 This bar graph shows how a group of pupils travelled to school.
Method of Travelling to School
Key points :
* Title
*Consistent Scale
*Labelling of axes
inc units
9
Number of Pupils
8
7
6
5
4
3
2
1
0
Walk
Bus
Car
Cycle
Method
Notice that the bar graph has gaps between the information and is used for
categories (meaning that the order can be changed).
34
Information Handling : Line Graphs
MTH 3-21a: I can display data in a clear way using a suitable scale, by choosing
appropriately from an extended range of tables, charts, diagrams and graphs, making
effective use of technology.
Line graphs consist of a series of points which are
plotted, then joined by a line. All graphs should
have a title, and each axis must be labelled. The
trend of a graph is a general description of it.
Example 1 The graph below shows a teacher’s weight over 14 weeks
as he follows an exercise programme.
Heather's weight
85
Weight in kg.
80
75
70
65
60
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Week
The trend of the graph is that his weight is decreased over the 14
weeks he trained.
Example 2 Graph of temperatures in Edinburgh and Barcelona.
Average Maximum Daily Temperature
25
20
15
10
Month
Barcelona
35
Edinburgh
Dec
Nov
Oct
Sep
Aug
Jul
Jun
May
Apr
Mar
0
Feb
5
Jan
Temperature (Celsius)
30
Information Handling : Scatter Graphs
MTH 3-21a: I can display data in a clear way using a suitable scale, by choosing
appropriately from an extended range of tables, charts, diagrams and graphs, making
effective use of technology.
A scatter diagram is used to display the
relationship between two variables.
A pattern may appear on the graph. This is called
a correlation.
Example
Arm
Span
(cm)
Height
(cm)
The table below shows the height and arm span of a group
of first year boys. This is then plotted as a series of
points on the graph below.
150
157
155
142
153
143
140
145
144
150
148
160
150
156
136
153
155
157
145
152
141
138
145
148
151
145
165
152
154
137
S1 Boys
170
165
Height
160
155
150
145
140
135
130
130
140
150
160
170
Arm Span
The graph shows a general trend, that as the arm span increases, so
does the height. This graph shows a positive correlation.
The line drawn is called the line of best fit. This line can be used to
provide estimates. For example, a boy of arm span 150cm would be
expected to have a height of around 151cm.
Note that in some subjects, it is a requirement that the axes start
from zero.
36
Information Handling : Pie Charts
MTH 3-21a: I can display data in a clear way using a suitable scale, by choosing
appropriately from an extended range of tables, charts, diagrams and graphs, making
effective use of technology.
A pie chart can be used to display information.
Each sector (slice) of the chart represents a
different category. The size of each category
can be worked out as a fraction of the total using
the number of divisions or by measuring angles.
Example
30 pupils were asked the colour of their eyes. The
results are shown in the pie chart below.
Eye C olour
Hazel
Blue
Brown
Green
How many pupils had brown eyes?
The pie chart is divided up into ten parts, so pupils with
2
brown eyes represent
of the total.
10
2
of 30 = 6 so 6 pupils had brown eyes.
10
If no divisions are marked, we can work out the fraction
by measuring the angle of each sector.
The angle in the brown sector is 72 .
so the number of pupils with brown eyes
72
=
x 30 = 6 pupils.
360
If finding all of the values, you can check your answers the total should be 30 pupils.
37
Information Handling : Pie Charts 2
MTH 3-21a: I can display data in a clear way using a suitable scale, by choosing
appropriately from an extended range of tables, charts, diagrams and graphs, making
effective use of technology.
Drawing Pie Charts
On a pie chart, the size of the angle for each
sector is calculated
as a fraction of 360 .
Statistics
Example: In a survey about television programmes, a group of people
were asked what was their favourite soap. Their answers are given in
the table below. Draw a pie chart to illustrate the information.
Soap
Eastenders
Coronation Street
Emmerdale
Hollyoaks
None
Number of people
28
24
10
12
6
Total number of people = 80
Eastenders
Coronation Street
Emmerdale
Hollyoaks
None
28
80
24
=
80
10
=
80
12
=
80
6
=
80
28
80
24
80
10
80
12
80
6
80
=
360
126
360
108
360
45
360
54
360
27
Favourite Soap Operas
None
Hollyoaks
Eastenders
Emmerdale
Coronation
Street
38
Check that the total =
360
Information Handling : Averages
MTH 3-20b: When analysing information or collecting data of my own, I can use my
understanding of how bias may arise and how sample size can affect precision, to
ensure that the data allows for fair conclusions to be drawn.
To provide information about a set of data, the
average value may be given. There are 3 ways of
finding the average value – the mean, the median
and the mode.
Mean
The mean is found by adding all the data together and dividing by the
number of values.
Median
The median is the middle value when all the data is written in numerical
order (if there are two middle values, the median is half-way between
these values).
Mode
The mode is the value that occurs most often.
Range
The range of a set of data is a measure of spread.
Range = Highest value – Lowest value
Example Class 1A4 scored the following marks for their homework
assignment. Find the mean, median, mode and range of the results.
7,
9,
7,
5,
6,
7,
10,
9,
8,
4,
8,
5,
7 9 7 5 6 7 10 9 8 4 8 5 7 10
14
102
7.285...
=
Mean = 7.3 to 1 decimal place
14
Mean =
Ordered values: 4, 5, 5, 6, 7, 7, 7, 7, 8, 8, 9, 9, 10, 10
Median = 7
7 is the most frequent mark, so Mode = 7
Range = 10 – 4 = 6
39
7,
10
Angles
MTH 3-17a: I can name angles and find their sizes using my knowledge of the
properties of a range of 2D shapes and the angle properties associated with
intersecting and parallel lines.
Types of angles
Obtuse > 90° and < 180°
Right Angle 90°
Acute < 90°
1 full turn
or
revolution
360°
Reflex
> 180° and < 360°
Straight Line 180°
Complementary Angles
When two angles can fit together
to make a right angle we say they
are complementary
a
b
Supplementary Angles
When two angles fit together to
make a straight angle we say they
are supplementary
a + b = 90°
Angles Round a point always
add up to 360o
a
a + b + c = 360o c
b
d
c + d = 180°
c
Angles vertically opposite each
other are equal
b
a
a
b
Naming Angles
To name an angle you need three capital
letters with the middle letter where the
angle is eg this is
ABC
A
C
B
Angles inside shapes
All
Quadrilaterals
All
Triangles
All internal angles in a
quadrilateral add up to 360°
All internal angles
add up to 180°
40
Co-ordinates
MTH 3-18a: I can use my knowledge of the coordinate system to plot and describe
the location of a point on a grid.
Co-ordinates are used to locate a point on a grid.
To locate a point, A, on the grid, going along 2 and up one, we would write this as A(2,1).
The point B, you go along 3 and up 4 and would write as B ( 3, 4 )
Note, the origin is the point ( 0, 0 )
Y (up)
7
6
5
B
4
3
2
A
1
0
1
2
3
4
41
5
6
X (across)
Pythagoras
MTH 4-16a: I have explored the relationships that exist between the sides, or sides and
angles, in right-angled triangles and can select and use an appropriate strategy to solve
related problems, interpreting my answer for the context.
Pythagoras theorem states the relationship between the lengths of
the three sides of a right angled triangle.
The theorem states that the hypotenuse squared equals the sum of
the squares of the two shorter sides.
Pupils are always encouraged to sketch the diagram of the triangle.
Examples are shown below,
Step 1 : Find Hypotenuse ( opposite right angle )
Step 2 : Write Pythagoras’s rule ( hypotenuse squared = sum of
squares on other two sides )
Step 3 : Solve.
x2
=
62
+
82
=
36
+
64
=
100
x
=
√100
x
=
10
X cm
6 cm
8 cm
102 =
x2
+
62
100 =
x2
+
36
-36
=
x2
√64 =
x
64
10 cm
6 cm
x cm
42
-36
8
=
x
x
=
8
Mathematical Dictionary (Key words):
Add; Addition
(+)
a.m.
Approximate
Calculate
Data
Denominator
Difference (-)
Division ( )
Double
Equals (=)
Equivalent
fractions
Estimate
Evaluate
Even
Factor
Frequency
Greater than (>)
Greater than or
equal to ( ≥ )
Integer
Least
Less than (<)
Less than or
equal to ( < )
To combine 2 or more numbers to get one number (called the
sum or the total)
Example: 12+76 = 88
(ante meridiem) Any time in the morning (between midnight
and 12 noon).
An estimated answer, often obtained by rounding to nearest
10, 100 or decimal place.
Find the answer to a problem. It doesn’t mean that you must
use a calculator!
A collection of information (may include facts, numbers or
measurements).
The bottom number in a fraction (the number of parts into
which the whole is split).
The amount between two numbers (subtraction).
Example: The difference between 50 and 36 is 14
50 – 36 = 14
Sharing a number into equal parts.
24 6 = 4
Multiply by 2.
Makes or has the same amount as.
Fractions which have the same value.
6
1
Example
and
are equivalent fractions
2
12
To make an approximate or rough answer, often by rounding.
To work out the answer.
A number that is divisible by 2.
Even numbers end with 0, 2, 4, 6 or 8.
A number which divides exactly into another number, leaving
no remainder.
Example: The factors of 15 are 1, 3, 5, 15.
How often something happens. In a set of data, the number of
times a number or category occurs.
Is bigger or more than.
Example: 10 is greater than 6.
10 > 6
Is bigger than OR equal to.
A whole number that can be either positive or negative or
zero.
The lowest number in a group (minimum).
Is smaller or lower than.
Example: 15 is less than 21. 15 < 21.
Is smaller than OR equal to.
43
Maximum
Mean
Median
Minimum
Minus (-)
Mode
Most
Multiple
Multiply (x)
Negative
Number
Numerator
Odd Number
Operations
Order of
operations
Place value
p.m.
Polygon
Prime Number
Product
Quadrilateral
Quotient
Remainder
Share
Sum
Square Numbers
Total
The largest or highest number in a group.
The arithmetic average of a set of numbers (see p32)
Another type of average - the middle number of an ordered
set of data (see p32)
The smallest or lowest number in a group.
To subtract. (sometimes referred to as take away)
Another type of average – the most frequent number or
category (see p32)
The largest or highest number in a group (maximum).
A number which can be divided by a particular number, leaving
no remainder.
Example Some of the multiples of 4 are 8, 16, 48, 72
To combine an amount a particular number of times.
Example 6 x 4 = 24
A number less than zero. Shown by a minus sign.
Example -5 is a negative number.
The top number in a fraction.
A number which is not divisible by 2.
Odd numbers end in 1 ,3 ,5 ,7 or 9.
The four basic operations are addition, subtraction,
multiplication and division.
The order in which operations should be done. BODMAS (see
p9)
The value of a digit dependent on its place in the number.
Example: in the number 1573.4, the 5 has a place value
of 100.
(post meridiem) Any time in the afternoon or evening
(between 12 noon and midnight).
A plane shape (2-D Shape) which has three or more straight
sides.
A number that has exactly 2 factors (can only be divided by
itself and 1). Note that 1 is not a prime number as it only has
1 factor.
The answer when two numbers are multiplied together.
Example: The product of 5 and 4 is 20.
A polygon with four sides
The number resulting by dividing one number by another.
Example: 20 ÷ 2 = 10, the quotient is 10
The amount left over when dividing a number.
To divide into equal groups.
The total of a group of numbers (found by adding).
A number that results from multiplying another number by
itself.
The sum of a group of numbers (found by adding).
44
45
S1/S2 Course Outline
S1 Unit 1 :
August -> September Weekend
Whole Numbers / Decimals / Money
S1 Unit 2 :
September Weekend -> Christmas vacation
Algebra – like terms. Level 4 extension : Factorising / Angles
S1 Unit 3 :
January -> March
Information Handling / Time and temperature
S1 Unit 4 :
March -> June
Position and Movement & Scale Drawings /
Algebra – equations
S2 Unit 1 :
August -> September
Measurement – length, Level 4 extension : Pythagoras /
Symmetry / Algebra
S2 Unit 2 :
October - > December
Area / Sequences / Angles
S2 Unit 3 :
January -> March
Triangles / Ratio & Proportion / Time : Extension Time,Distance,Speed
S2 Unit 4 :
April -> June
Fractions & Percentages / Information Handling / 2D & 3D shapes
Note other work that is carried out during each year includes units on ‘History of Maths’,
problem solving, group projects. All through the school year, pupils will be given opportunities
to practice their numeracy skills in class and at home. We always encourage pupils to
complete tasks without a calculator wherever possible.
46
Useful Websites
There are many valuable online sites that can offer help and more practice. Many are
presented in a games format to make it more enjoyable for your child.
The following sites have been found to be useful.
www.amathsdictionaryforkids.com
www.woodlands-juniorschool.kent.sch.uk
www.bbc.co.uk/schools/bitesize
www.topmarks.co.uk
www.primaryresources.co.uk/maths
www.mathsrevision.com
However the following site will give you links to a huge selection of relevant websites already
matched to the Renfrewshire maths planners.
http://delicious.com/renfrewshiremaths
You can also get apps for mobile devices. We have found this app useful :
Fun Maths4kids
47