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Units of Measurement
Area
Did you know that
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the hunting area of a pack of wolves is 1 000 m2?
the surface area of a dragonfly's wings is 1 380 mm2?
the largest leaves are found on the Abcasia maerorrhiza plant of East Malaysia; each leaf has a surface area of 317 m2? |
The abbreviations used by scientists for the units of area are as follows:
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Abbreviation |
Area |
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km2 |
square kilometre |
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ha |
hectare |
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m2 |
square metre |
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cm2 |
square centimetre |
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mm2 |
square millimetre |
The relationship between these units of area is:
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Unit of Area |
Relationship |
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1 km2 = 1 000 000 m2
1 ha = 10 000 m2
1 m2 = 10 000 cm2
1 cm2 = 100 mm2 |
Length
Did you know that
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a blue whale is 33,6 m long?
a giant squid is 17 m long?
the eucalyptus plant can reach 132 m in height?
the tallest man is 2,72 m in height?
the deepest roots reach 120 m into the soil? |
The abbreviations used by scientists for the units of length are as follows:
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Abbreviation |
Length |
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km |
kilometre |
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m |
metre |
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cm |
centimetre |
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mm |
millimetre |
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µm |
micrometre |
The relationship between these units of length is:
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Unit of Length |
Relationship |
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1 km = 1000 m
1 m = 100 cm
1 cm = 10 mm
1mm = 1000 µm |
Load
The load is the amount of mass carried by a certain unit of area. For example, the load on an insect's wings is measured as the body mass of the insect divided by the surface area of its wings.
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body mass : wing surface area = load
in mg/mm2 |
Mass
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The most massive living organism on Earth is a plant. It is called the giant sequoia which can have a mass of 2500 tonnes, including its roots?
A housefly has a mass of 12mg?
The dolphin has a mass of around 40kg? |
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Abbreviation |
Units of Mass |
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tonnes |
tonnes |
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kg |
kilogramme |
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g |
gramme |
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mg |
milligramme |
Speed
Speed measures the movement of something in a certain time interval. For example, we can measure the speed of the movement of an animal in
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metres per hour = m/h
or kilometres per hour = km/h |
For other measurements, such as the rate of your heartbeat, we would use the measurement
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beats per minute = beats/min |
Or, for the movement of an insect's wings, we would study the
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beats per second = beats/s |
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The cheetah has a maximum speed of 115 km/h.
The snail slithers along at a maximum speed of 0,83 m/min.
The tuna swims at a maximum speed of 80 km/h.
The sap in a tree moves at a speed of 100cm/h. |
Time
The abbreviations for the units of time are:
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Abbreviation |
Units of Time |
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h |
hour |
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min |
minute |
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s |
seconds |
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Remember that:
60 minutes = 1 hour
60 seconds = 1 minute
so 1 min 30 s = 1,5 min (not 1,30 min) |
Volume
Did you know that
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an elephant needs to drink between between 70dm3 and 90dm3 of water each day?
a man with a mass of 70kg has 5,645dm3 of blood in his body?
the human lungs can hold a maximum of 6dm3 of air? |
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Abbreviation |
Area |
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m3 |
cubic metre |
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dm3 |
cubic decimetre |
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cm3 |
cubic centimetre |
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mm3 |
cubic millimetre |
The relationship between these units of area is:
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Unit of Volume |
Relationship |
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1 cm3 = 1 000 m3
1 dm3 = 1 000 cm3
(note that 1 dm3 used to be called 1 litre) |
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