Name of Lecturer: Mr. J.Agius
Course: FCES
LESSON 32
Measurement
32.1 Metric and Imperial Units
In 1971 the British monetary system was decimalised. They stopped using pounds, shillings
and pence (£ s d) and started using pounds and ‘new’ pence (£ p). Since then, many more
units have changed from imperial to metric units:
We now buy petrol in litres, not gallons.
We buy material in metres instead of yards.
The standard length of a ruler is 30 centimetres, not 12 inches.
The weather forecast gives temperatures in degrees Celsius rather than in degrees Fahrenheit.
We do, however, still use some imperial measures:
Distances are given in miles and speed restrictions in miles per hour.
Although most grocery items are labelled with weights in both grams and ounces, fruit,
vegetables and sweets are priced in pounds and ounces as well as in kilograms.
Milk and beer are still sold in pints.
Carpets are often sold in feet and yards.
The advantage of the metric system over the imperial is the ease with which one unit can be
converted to another.
The USA still uses imperial units.
32.2 Metric units
The metric system is a decimal system and units are converted by multiplying or dividing by
powers of 10 (i.e. 10, 100, 1000).
Each prefix to a standard measure (e.g. metre, gram, litre) indicates the relative size:
kilo (k)
means 1000 
deci (d)
hecto (H)
means 100 
centi (c)
deka (D)
means 10 
milli (m)
1

10
1
means

100
1
means

1000
means
Learning Outcome 5 – Classify, draw and work with various shapes and objects
Page 1
Name of Lecturer: Mr. J.Agius
Course: FCES
The most common metric units in everyday use are:
Length
Metre (m)
10 mm = 1 cm
100 cm = 1m
1000 m = 1 km
Weight
Gram (g)
1000 mg = 1 g
1000 g = 1 kg
1000 kg = 1 tonne
Capacity
Litre (l)
1000 ml = 1 l
1000 cm3 = 1 l
1 cm3 = 1 ml
Example 32A
a)
b)
Change 2 kilometres to metres
Change 250 mm to cm
Answers
a)
Kilometres are larger units than metres.
Multiply by the number of metres
In a kilometre, which is 1000.
2 km = 2  1000 m = 2000 m
b)
Millimetres are smaller units than centimetres. Divide by the number of
millimetres in a centimetre, which is 10.
250 mm = 250  10 cm = 25 cm
Exercise 32A
Do not use a calculator in this exercise.
1) Change these lengths to centimetres:
a) 3 m
b) 30 mm
c) 6 m
d) 100 mm
e) 350 mm
f)
g) 5 mm
h) 0.08 m
3.6 km
2) Change these lengths to millimetres:
a) 2 cm
b) 5 cm
c) 20 cm
d) 60 km
3) Change these lengths to metres:
a) 5 km
b) 300 cm
c) 10 km
d) 2000 cm
e) 250 cm
f)
0.04 km
Learning Outcome 5 – Classify, draw and work with various shapes and objects
Page 2
Name of Lecturer: Mr. J.Agius
Course: FCES
4) Change these weights to grams:
a) 5 kg
b) 40 kg
c) 250 kg
d) 6500 mg
5) Change these volumes to litres:
a) 3000 ml
b) 8000 ml
c) 50 000 cm3
d) 50 ml
6) Change these volumes to millilitres:
a) 6 l
b) 40 l
c) 350 l
d) 200 cm3
7) Change these lengths to kilometres:
a) 3000 m
b) 45 000 m
8) Change these weights to kilograms:
a) 2000 g
b) 3 tonnes
c) 50 000 g
d) 325 g
9)
Jim’s lorry weighs 8 tonnes. How many grams is this?
10)
Jeremy walks 10 kilometres. How many centimetres is this?
11)
Gerry has an average pace length of 75 cm.
How many paces does she take in 3 km?
12)
Write down the number of milligrams in 1 kilogram.
13)
How many 75 ml glasses can be filled from bottle holding 1.5 l of cola?
14)
How many 50 mm pieces of wood can be cut from a piece of wood of length 3 m
assuming there is no waste?
Learning Outcome 5 – Classify, draw and work with various shapes and objects
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Name of Lecturer: Mr. J.Agius
Course: FCES
32.3 Measuring Time
Of all the measures used in everyday life, time is probably used most often. After all, you
always want to know when your maths lesson will finish!
You need to be able to tell the difference between the times in the morning and times in the
afternoon and evening.
There are two ways of doing this:
 Use am for morning and pm for afternoon and evening
 Use the 24-hour clock system that is used on bus and train timetables.
This table shows some times of day under both systems:
Using am and pm
Using the 24-hour clock
12:00 midnight
9 am
12:00 noon
3:30 pm
00:00 or 24:00
09:00
12:00
15:30
In the morning the time shown by these clocks is
9:25 am or 09:25 or twenty five past nine in the
morning.
In the afternoon the time shown by these clocks is
1:35 pm or 13:35 or twenty five to two in the
afternoon.
When the time is after 12 noon you add 12 to the hour number to get the 24-hour clock time.
Exercise 32B
1) Write these times as you would say them:
a) 11:00
b) 9:15
c) 22:50
d) 3:05
e) 15:40
f)
12:20
Learning Outcome 5 – Classify, draw and work with various shapes and objects
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Name of Lecturer: Mr. J.Agius
Course: FCES
2) Change these times from am and pm to 24-hour clock times:
a) 10:00 am
b) 10:00 pm
c) 9:30 am
d) 9:30 pm
e) 8:20 pm
f)
g) 7 am
h) 8 pm
8:20 am
3) Write these times using the 24-hour clock:
a) 5:50 pm
b) 5:50 am
c) 11 pm
d) 8 am
e) quarter past 8 in the morning
f)
g) five to three in the afternoon
h) twenty to seven in the morning
quarter to 9 in the evening
4) Change these times from 24-hour clock times to am or pm:
a) 08:00
b) 09:20
c) 21:30
d) 13:10
e) 12:10
f)
00:20
5) Write these times using am or pm:
a) 16:30
b) 21:10
c) 23:55
d) 13:10
e) 06:25
f)
00:00
Learning Outcome 5 – Classify, draw and work with various shapes and objects
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Name of Lecturer: Mr. J.Agius
Course: FCES
32.4 Calculating Time

You need to know these:
60 seconds
60 minutes
24 hours
365 days
366 days
= 1 minute
= 1 hour
= 1 day
= 1 year
= 1 leap year
Example 32C
a)
b)
Change 135 minutes to hour and minutes.
How many minutes are there in 3 hours?
Answer
135  60 = 2.25 hours
Do NOT write this as 2 hours 25 minutes as this would be wrong.
a)
To change the 0.25 hours to minutes you must multiply 0.25 by 60 because there are 60
minutes in an hour.
0.25  60 = 15 minutes
So
135 minutes is 2 hours 15 minutes.
3 hours = 3  60 minutes = 180 minutes
b)
Exercise 32C
1) Change these times into minutes:
a) 2 hours
b) 5 hours
c) 2 hours 30 minutes
d) 5 ½ hours
e) 6 ¼ hours
f)
5 hours 15 minutes
2) Change these times into hours:
a) 180 minutes
b) 240 minutes
c) 75 minutes
d) 260 minutes
e) 325 minutes
f)
g) 3 days
h) 5 ½ days
i)
j)
500 minutes
90 minutes
1 week
Learning Outcome 5 – Classify, draw and work with various shapes and objects
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Name of Lecturer: Mr. J.Agius
Course: FCES
3)
How many seconds are there in 1 hour?
4)
How many minutes are there in 1 day?
5)
How many seconds are there in a year?
When you make calculations with time values you have to be careful with the ‘carry’ digit.
Example 32D
a)
b)
Add 2 ½ hours to the time of 10:40.
Take 3 hours 15 minutes away from 11:10.
Answers
a)
10:40 +
2:30
13:10
1
b)
11:10 –
3:15
7:55
Don’t forget 60 minutes make 1 hour.
So
70 minutes = 1 hour 10 minutes
40 + 30 = 70 minutes or 1 hour 10 minutes
The ‘carry’ digit represents 1 lot of 60 minutes
You have to ‘borrow’ 60 minutes so 70 – 15 gives 55.
You might find it easier to write 11:10
as 10:70 to do this calculation.
Exercise 32D
1) Add 15 minutes to each of these times:
a) 10:30
b) 09:45
c) 11:40
d) 08:05
2) Add 50 minutes to each of these times:
a) 09:00
b) 10:30
c) 11:40
d) 08:05
3) Add 2 hours 40 minutes to each of these times:
a) 09:40
b) 10:45
c) 11:50
d) 06:10
Learning Outcome 5 – Classify, draw and work with various shapes and objects
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Name of Lecturer: Mr. J.Agius
Course: FCES
4) Add 12 hours 45 minutes to each of the following:
a) 02:30
b) 07:15
c) 10:50
d) 6:45
5) Subtract 15 minutes from each of these times:
a) 09:55
b) 11:40
c) 08:10
d) 09:05
6) Subtract 50 minutes from each of these times:
a) 08:55
b) 11:40
c) 10:30
d) 09:00
7) Subtract 2 hours 30 minutes from each of these times:
a) 09:55
b) 11:40
c) 08:10
d) 09:05
8) Subtract 12 hours 45 minutes from each of these times:
a) 14:50
b) 19:30
c) 17:00
d) 18:45
Mixed Exercise
1) Convert
a) 2 m into cm
b) 3 km into m
c) 40 mm into cm
d) 6 feet into inches
e) 1.3 m into mm
f)
18 yards into feet
2) Convert
a) 1.2 kg into g
b) 10 stones into pounds
c) 250 g into kg
d) Half a pound into ounces
Learning Outcome 5 – Classify, draw and work with various shapes and objects
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Name of Lecturer: Mr. J.Agius
Course: FCES
3) Convert
a) 1.5 litres into ml
b) 10 pints into gallons
c) 70 cl into litres
d) Half a gallon into pints
4) Convert
a) 120 minutes into hours
b) 3 minutes into seconds
c) 90 seconds into minutes
d) 1 hour into seconds
Evening TV
5)
1800
The News
1830
Local News
1840
Tennis Highlights
1915
Top of the Pops
a) How long does The news last?
b) How long does the Local news last?
c) What programme is on at quarter to seven?
d) How long does Tennis highlights last?
6) Paul buys three 330ml cans and Emily buys a litre bottle.
a) Who gets more and by how much?
b) Give two possible reasons why Paul bought the cans rather than a bottle.
Annabel needs 1 kg of margarine.
7) The shop has no 1 kg tubs but it does have 500g tubs and 250g tubs.
Give three ways in which Annabel can make up 1 kg of margarine.
Hugh’s office has a shelf 1.2m long.
Hugh has 16 box files.
8)
Each box file is 7 cm thick.
Will they all fit on the shelf?
Learning Outcome 5 – Classify, draw and work with various shapes and objects
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