Page 516 - Canadian BC Science 9

498 MHR • Science Skill 13
Science Skill 13
Units of Measurement and Scientific Notation
Commonly Used Metric Prefixes
Prefixes
Symbol
Relationship to the Base Unit
giga-
G
109 = 1 000 000 000
mega-
M
106 = 1 000 000
kilo-
k
103 = 1 000
hecto-
h
102 = 100
deca-
da
101 = 10
–
–
100 = 1
deci-
d
10–1 = 0.1
centi-
c
10–2 = 0.01
milli-
m
10–3 = 0.001
micro-
􏰈
10–6 = 0.000 001
nano-
n
10–9 = 0.000 000 001
Throughout history, people have developed systems of numbering and measurement. When different groups of people began to communicate with each other, they discovered that their systems and units of measurement were different. Some groups within societies created their own unique systems of measurement.
Today, scientists around the world use the metric system of numbers and units. The metric system is the official system of measurement in Canada.
The Metric System
The metric system is based on multiples of
10. For example, the basic unit of length is the metre. All larger units of length are expressed in units based on metres multiplied by 10, 100, 1000, or more. Smaller units of length are expressed in units based on metres divided by 10, 100, 1000, or more.
Each multiple of 10 has its own prefix (a word joined to the beginning of another word). For example, “kilo-” means multiplied by 1000. Thus, one kilometre is 1000 metres.
1 km 􏰀 1000 m
The prefix “milli-” means divided by 1000. Thus, one millimetre is one-thousandth of a metre.
1mm􏰀 1 m 1000
In the metric system, the same prefixes are used for nearly all types of measure, such as mass, weight, area, and energy. A table of the most common metric prefixes is given at the top of the next column.
Example 1
The distance from Penticton to Prince Rupert is 1431 km. Express this distance in metres.
Solution
1431 km 􏰀 ? m
1 km 􏰀 1000 m
1431 km 􏰀 1431 􏰁 1000 m 􏰀 1 431 000 m
Example 2
There are 250 g of cereal in a package. Express this mass in kilograms.
Solution
1kg 􏰀1000g 250g􏰁4 􏰀1000g
1000g 􏰀250g 4
14 k g 􏰀 0 . 2 5 k g
The next table lists most of the frequently used metric quantities you will encounter in your science classes.