l Any measurement is always a multiple of some basic units.
(Ex. 5g = 1g × 5 ... 5g is a multiple of 1g)
l Measurements can be described in a different unit.
(Ex. 1km = 1000m = 100000cm)
Quantities
Measurements have two parts- the number and the unit. Number and unit together= quantity. In Canada, we use SI (Système International) unit system to describe a measurement.
l SI System
SI system is a French system, that dates back to the early 1800`s using power of 10.
lSI Base Units
Measurement | Unit | Abbreviation |
length | metre | m |
time | second | s |
mass | gram | g |
amount of substance | mole | mol |
luminous intensity | candela | cd |
temperature | Kelvin | K |
electric current | ampere | A |
Conversions
When converting the two units, use “MAGIC ONE”!!!
l Big unit to small unit :
(original measurement+its unit)x
(power of 10 for measurement+ unit converting to)/（1+its unit）
(power of 10 for measurement+ unit converting to)/（1+its unit）
l Ex. Converting 2Gg to g
2Gg×109g/1Gg = 2×109g
l Small unit to big unit:
l Small unit to big unit:
(original measurement+its unit)x(1+unit converting into)/(power of 10 for measurement+original unit）
l Ex. Converting 2ns to s
2ns×1s/109ns= 2×10-9s
Here is a video that talks more about measurements!
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