Conversion of Metric Units
April 2011. Kindly contributed by Joaquin Llorente, Trafford College.
Search for Joaquin on www.skillsworkshop.org
Visit the download page for this resource to find detailed teaching notes,
curriculum links and related resources.
Curriculum links
Adult Numeracy
MSS1/E3.5 (3.6) ((3.7)) Read, estimate, measure and compare length (weight) ((capacity))using common and
standard units (b) Know that 10mm = 1cm, 1000mm = 1m; 1000g = 1 kg; 1000ml = 1 litre.
MSS1/L1.7 Convert units of measure in the same system (a) know the relationship between metric units
MSS1/L2.5 Calculate with units of measure within the same system (a) know the relationship between metric units
and for underpinning Functional Mathematics
Entry 3: Use metric units in everyday situations.
Level 1: Convert units of measure in the same system.
Level 2: Use, convert and calculate using metric and, where appropriate, Imperial measures.
Conversion of Metric Units
The Metric System
• The International Metric System was
developed and introduced in Europe in the
times of Napoleon
• It is based on the decimal numbering
system
• Conversion factors are always powers of
10 (i.e. larger units are 10, 100, 1000 of
the base unit and smaller units are 1/10,
1/100, 1/1000 of the base unit)
The seven column table
This table and 3 simple rules will be the key to converting between units
successfully
The middle column, with red borders, will hold the basic unit, metre (m), litre (l)
or gram (g)
Larger units such as kilometre (km) or kilogram (kg) will go to the left and
smaller subunits such as centimetre (cm), millimetre (mm), centilitre (cl),
millilitre (ml) or milligram (mg) will go to the right
Metric Units - Distance
m
The base unit for measuring distance is the metre (m)
We use metres to measure:
• The height of a door
• The length of a corridor
• The length and width of a room
Metric Units - Distance
km
m
We use kilometres (km) for longer distances, such as:
• The distance between cities (for example, between
Madrid and Barcelona, or Manchester and Leeds)
• The distance to the next services on the motorway
• The distance from the Earth to the moon (400 000 km)
Metric Units - Distance
km
m
mm
We use millimetres (mm) for very small things:
• The thickness of a coin
• The diameter of a screw
Metric Units - Distance
km
m
cm
We use centimetres (cm) for things like:
• The width or depth of a washing machine
• The height of a table
• The width of a shelf
mm
Metric Units - Distance
km
m
cm
mm
There are other units in the empty columns, but
we rarely see or use their names.
Check point 1
• How many columns do you need for the
Metric Unit Conversion Table?
In the Metric System …
• What is the basic unit for distance?
• What other metric units for distance do
you remember?
• Can you place them in the table?
Using the 7 column table
• In the next few slides we are going to see
how to use this table to convert between
m, km, mm and cm.
• We will start by writing the original
measurement on the table
• Then we will see how to convert into the
desired unit
Convert 32 cm into mm
STEP 1 - Write the original measurement into
the table
3 2
km
cm
m
cm
3
2
mm
Convert 32 cm into mm
STEP 2 – Put the decimal point to the right of
the target unit
3 2
km
cm =
m
3
mm
cm
mm
2
.
Convert 32 cm into mm
STEP 3 – Fill in with 0s as required
3 2
km
cm =
m
320 mm
cm
3
2
mm
0.
Examples - STEP 1
km
m
cm
mm
Write on the table:
5m
5
3 km
3
2
5
1
2
7
27 mm
512 cm
Examples - STEP 2
km
m
.
3
cm
mm
5m
=
km
3 km
=
m
2. 7
27 mm
=
cm
2
512 cm
5
.
5. 1
Place the decimal point:
=
m
Examples - STEP 3
km
m
cm
mm
Fill any gaps with 0s:
0 . 0
0
5
5m
=
0.005
km
3
0
0 .
3 km
=
3 000
m
2. 7
27 mm
=
2.7
cm
2
512 cm
5.12
m
0
5. 1
=
Check point 2
• Draw the table and the column headings
for distance
• Use the table to convert the following
numbers into cm:
350 m
78 mm
5 km
3 mm
Metric Units - Weight
g
The base unit for measuring weight is the gram (g)
• A sugar cube weighs a few grams
• We use grams to weigh sliced ham (200 g)
Metric Units - Weight
kg
g
A more familiar unit for weight is the kilogram (kg):
• A bag of sugar weighs 1 kg
• A normal wash-load is 1.5 kg
• My weight is about 81 kg
Metric Units - Weight
kg
g
We use milligrams (mg) for very small things:
• The amount of paracetamol in a tablet
mg
Metric Units - Capacity
l
The base unit for measuring distance is the litre (l)
• A large bottle of Coke contains 2 l:
• The petrol tank of an average car holds 40 l
Metric Units - Capacity
kl
l
• Kilolitres (kl) are rarely used in everyday life
• The capacity of a swimming pool could be
measured in kl but is more commonly measured
in thousands of litres instead
Metric Units - Capacity
kl
l
• A teaspoon is about 5 ml
• A can of coke is bout 330 ml
ml
Metric Units - Capacity
kl
l
• A bottle of wine is 75 cl
• A drinking cup (paper) is about 20 cl
cl
ml
Metric Units - Summary
km
m
kg
g
l
cm
mm
mg
cl
ml
Conversion of Metric Units
Harder examples
Convert 3.2 kg into g
STEP 1 - Write the original measurement into
the table
3. 2
kg
3 .
g
2
kg
mg
Convert 3.2 kg into g
STEP 2 – Put the decimal point to the right of
the target unit
3. 2
kg
3 .
g
2
kg =
g
mg
Convert 3.2 kg into g
STEP 3 – Fill any gaps with 0s
3. 2
kg
3
g
2
0
0 .
kg = 3 200
g
mg
Check point 3
In the Metric System…
• What is the base unit for weight?
• What other weight units can you
remember?
• What is the base unit for capacity?
• What other units of capacity can you
remember?
Harder examples - STEP 1
km
kg
m
g
l
cm
cl
mm
mg
ml
0.5 m
0. 5
3.
Write on the table:
3.5 kg
5
2. 7
5
1. 2
2.7 cl
51.2 m
Harder examples - STEP 2
km
kg
m
g
l
cm
cl
mm
mg
ml
0.5 m
0. 5
3.
5
2. 7
5
1. 2
Move the decimal point:
=
cm
3.5 kg =
mg
2.7 cl
=
ml
51.2 m =
km
Harder examples - STEP 3
km
kg
3
m
g
l
5
0 . 0
0
5
cm
cl
mm
mg
ml
Fill any gaps with 0s:
0.5 m
50
cm
0
5
0 .
0
0
0
0 . 3.5 kg
= 3 500 000 mg
2
7 . 2.7 cl
=
27 ml
51.2 m =
0.0512 km
1
2
=
Check point 4
Use the conversion table to answer these
questions:
•
•
•
•
•
How many cm in 1 m?
How many cl in 2 l?
How many g in 1kg?
1m is the same as _________ km
1mg is the same as __________ g