
Units of Measurement
Area
Did you know that
the hunting area of a pack of wolves is 1 000 m^{2}?
the surface area of a dragonfly's wings is 1 380 mm^{2}?
the largest leaves are found on the Abcasia maerorrhiza plant of East Malaysia; each leaf has a surface area of 317 m^{2}? 
The abbreviations used by scientists for the units of area are as follows:
Abbreviation 
Area 
km^{2} 
square kilometre 
ha 
hectare 
m^{2} 
square metre 
cm^{2} 
square centimetre 
mm^{2} 
square millimetre 
The relationship between these units of area is:
Unit of Area 
Relationship 
1 km^{2} = 1 000 000 m^{2}
1 ha = 10 000 m^{2}
1 m^{2} = 10 000 cm^{2}
1 cm^{2} = 100 mm^{2} 
Length
Did you know that
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:
Abbreviation 
Length 
km 
kilometre 
m 
metre 
cm 
centimetre 
mm 
millimetre 
µm 
micrometre 
The relationship between these units of length is:
Unit of Length 
Relationship 
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.
body mass : wing surface area = load in mg/mm^{2 } 
Mass
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? 
Abbreviation 
Units of Mass 
tonnes 
tonnes 
kg 
kilogramme 
g 
gramme 
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
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
beats per minute = beats/min 
Or, for the movement of an insect's wings, we would study the
beats per second = beats/s 
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:
Abbreviation 
Units of Time 
h 
hour 
min 
minute 
s 
seconds 
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
an elephant needs to drink between between 70dm^{3} and 90dm^{3} of water each day?
a man with a mass of 70kg has 5,645dm^{3} of blood in his body?
the human lungs can hold a maximum of 6dm^{3 }of air? 
Abbreviation 
Area 
m^{3} 
cubic metre 
dm^{3} 
cubic decimetre 
cm^{3} 
cubic centimetre 
mm^{3} 
cubic millimetre 
The relationship between these units of area is:
Unit of Volume 
Relationship 
1 cm^{3} = 1 000 m^{3}
1 dm^{3} = 1 000 cm^{3}
(note that 1 dm^{3} used to be called 1 litre) 

