Transcript Number_Estimation, Assumptions and Predictionsx

Estimation, assumptions
and predictions
Estimating calculations
You would have covered estimating calculations in
GCSE.
Round the following numbers to 1 sig. fig.:
A) 2520
B) 324,566
C) 2.565
D) 0.0234
E) 0.657
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On whiteboards!
On a long-haul flight an
aeroplane flew 3123 miles in 8.4 hours.
Work out an estimate of how many miles
it flew each hour.
a) 4000
3
b) 40
c) 400
On whiteboards!
Estimate the answer
to this question:
54.6 x 2.91
a) 1650
b) 165
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c) 16.5
On whiteboards!
Martyn rode 287 kilometres
in 11 days. Roughly how many
kilometres did he ride
each day?
a) 30
b) 300
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c) 3
On whiteboards!
Estimate the answer
to this question:
2.1 x 9.4 x 3.7
a) 75
b) 750
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c) 0.75
On whiteboards!
A square has edges of length 2.44cm.
What is an estimate of the area?
a) 6cm²
b) 60cm²
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c) 0.6cm²
On whiteboards!
Estimate the answer to this question:
935 x 29
a) 27000
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b) 2700
c) 270
On whiteboards!
At a theatre they sold 73 cups
of coffee during the interval
at 68p a cup. Estimate the amount
they took on coffee.
a) £5.00
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b) £500
c) £50
On whiteboards!
Estimate the answer to this question:
34.87 x 20.27
a) 70
b) 7000
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c) 700
On whiteboards!
At Dave’s ice cream stall
he sold 223 ice creams at 67p each.
Estimate how much his takings
were that day.
a) £150
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b) £15
c) £1.50
On whiteboards!
Estimate the answer to this question:
3.14 x 7.92
a) 250
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b) 25
c) 0.25
Estimation
You are used to estimating calculations
from GCSE but you now have to be able
to estimate real life problems.
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Question 1
What is the average height of a man in the UK?
257cm
107cm
177cm
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207cm
Question 2
What is the average weight of a man in the U.K?
78kg
54kg
153kg
15
28kg
Question 3
Average life span for a woman in England?
95
78
65
16
89
Question 4
The height of the express lift tower?
127m
256m
1350m
65m
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Question 5
Average age of a woman to have her first child in England
35
24
28
18
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Question 6
Distance from here to Sixfields stadium (walking distance)
0.5 miles
3 miles
5 miles
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1.5 miles
Question 7
How many seconds in a year?
35,787
31,557,600
314,567
3,456,678,876
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Question 8
Average number of people per household in the UK
0.9
1.4
2.3
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3.2
Question 9
Average wage for
a full time worker
in the U.K?
£36,500
£19,500
£12,500
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£26,500
Question 10
What is the average age of the maths department?
35
30
40
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Answers
1. C
6. D
2. A
7. B
3. D
8. C
4. A
9. D
5. C
10. B
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Fermi estimation
http://www.youtube.com/watch?v=0YzvupOX8Is
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Wembley stadium
What is the volume of
Wembley stadium?
Break this down into more accessible calculations:
 What is the width of Wembley stadium? (m)
 What is the length of Wembley stadium? (m)
 What is the height of Wembley stadium? (m)
 What is the volume of Wembley stadium? (m³)
Hint:for
The
area of a standard football pitch is 90m by 45m
Click
Hint
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How long is a toilet roll?
If you were to roll out a standard toilet roll, how
long would it be?
Click for hint
Hint: A standard piece of toilet paper is 11cm long.
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How many bricks are needed to build a garage?
average
Click for Hint:
HintThe average width of a car is 1.8m
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Estimate the distance
from John O’Groats
to Land’s End
Hint:
The distance from London to Cambridge
Click for
Hint
is 65 miles (driving)
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Using data to make predictions
What is this a picture of?
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Is climate change happening?
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Is climate change happening?
Look at the data sheet provided.
Can you use this to argue your case?
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Comparing temperatures from an
average in 30 years
Could you predict the average temperatures from
2011 to 2040?
By what per cent has it increased by?
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Mean temperatures each month
in the UK
http://www.metoffice.gov.uk/climate/uk/datasets/T
mean/date/UK.txt
Choose a month to look at:
How can we use this data to predict the mean
temperatures in 2020?
Or 2100?
Or 3100?
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Group the averages
Find the average for every ten years.
By what per cent is it increasing by each year?
Year
Average
temperature
(January)
Increase
from
previous
10 years
1910-1919
1920-1929
1930-1939
….
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Percentage
increase
Moving average
 Will looking at moving averages find a more
accurate picture?
 Create a 3-point moving average for the data in
the table. Then try a 4- and 5-point moving
average.
 Enter this on to a spreadsheet and graph the
temperature change over the last 100 years.
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