Transcript Handling Data 4 - Pie Charts

GCSE
Mathematics
Targeting Grade C
Handling Data
Unit 4 Pie Charts
Can you:
If not you need
TOP: Revise angles
Practice 1: How to draw a pie chart
•Draw a pie chart
•Answer questions from pie charts
Try a test
Practice 2: Answer questions
about pie charts
TAIL
TOP
1)
2)
3)
4)
5)
6)
7)
8)
Are you ready for
the answers ?
How many degrees in a circle?
How many degrees in a triangle?
How many degrees in a right angle?
How do we recognize a right angle?
What makes a triangle isosceles?
How do we know if a triangle is equilateral?
How many degrees in a quadrilateral?
What do we know about an interior and
exterior angle?
9)
What do all exterior angles add up to?
10) Write a fact about scalene triangles.
Lesson
Answers
1)
360º
2)
180º
3)
90º
4)
Looks like a square
5)
Two equal sides,
two equal angles
6)
All sides and
angles equal
7)
360º
8)
Add up to 180º
9)
360º
10) All sides and
angles are different
Practice 1:
1)
2)
Draw the pie charts from the tables below.
Activity
Frequency
Gym
4
Swimming
12
Squash
3
Aerobics
11
Total
30
Remember:
Step 1: Total frequency if
not given
Step 2: 360º  Total
Frequency
Step 3: Multiply each
group by the answer to
Step 2
Type of Pet
Frequency
Cat
30
Step 4: Draw the pie
chart
Dog
25
Step 5: Label carefully
Rabbit
15
Other
20
Total
90
Lesson
Practice 2:
1)
The pie chart shows how Jenny spends her monthly income.
Jenny spends £150 a month on food.
(a) Work out Jenny’s monthly income
(b) Work out how much Jenny spends on rent each month.
Clothes & Going
Out
Food
Savings
Other Bills
120º
Rent
Next
Put the angle in the pie chart over 360 (like
a fraction), cancel down if possible and then
relate it to the money Jenny has.
2)
The pie chart gives information about the bills paid by a Water
Company.
(a) Work out the size of the angle representing Wages.
The Water Company spent £18 000 on Materials.
(b) Work out the amount it spent on Rates.
Lesson
TAIL
1)
Patrick carried out a survey of 45 pupils in Year 11. He asked how
many books they had borrowed from the library in the last month.
These are Patrick’s results.
(a) Copy and complete the table.
Number of
books
0 to 2
3 to 5
6 to 8
more than 8
Tally
Frequency
6
(b) Construct a pie chart to show this information.
Are you ready for
the answers ?
Next
Answers to Q1
Number of
books
0 to 2
3 to 5
6 to 8
more than 8
Tally
Frequency
11
15
13
6
Angles : 11  8 = 88º
15  8 = 120º
13  8 = 104º
6  8 = 48º
Next
2) In a town, 1800 cars were stolen in a year. The table show information
about the times of day in which they were stolen.
Time
Number of cars
Midnight to 6 am
6 am to midday
Midday to 6 pm
6 pm to midnight
Time unknown
700
80
280
470
270
This information can be shown on a pie chart.
(a) Copy out the table below and work out the angles for each sector.
Time
Midnight to 6 am
6 am to midday
Midday to 6 pm
6 pm to midnight
Time unknown
Total of angles
Angle of sector
Are you ready for
the answers ?
360º
(b) Construct the pie chart.
(c) What fraction of cars were stolen between midday and 6pm. Write
your answer in its simplest terms.
Next
Answers to Q2.
Angles: 700  0.2 = 140º
80  0.2 = 16º
280  0.2 = 56º
470  0.2 = 94º
270  0.2 = 140º
(c) 280 = 7
1800
Lesson
45