2. Standards of measurement
What is a standard? A standard is an exact quantity that people agree to use to compare measurements

3. Units of mesurements What is missing in the below picture?
The length of the string ball is 150
For any measurement to make sense, it must include a number and a unit

4. Systems of units People in the world uses two systems of units:
English system
Metric system
Foot
Inch
Mile
Gallon
Pound
Minute
second
Meter
Centimeter
Kilometer
Liter
Kilogram
Minute
second

5. In the SI there are seven base units for seven base quantities
Scientists around the world uses a unified system of units called the SI (International System of Units).
In the SI there are seven base units for seven base quantities
Quantity Measured
Unit
Symbol
Length
meter m
Mass
kilogram Kg
Time
second s
Electric current
ampere A
Temperature
Kelvin K
Amount of Substance
mole
mol
Intensity of Light
Candela cd

6. SI is an easy system because it is based on multiples of 10.
Prefixes with units
are used to convert
to multiples and
parts of the units.
Prefix
Symbol
Multiplying Factor
Giga- G-
Mega- M-
Kilo- k-
1000
Deci- d-
0.1
Centi- c-
0.01
Milli- m-
0.001
Micro- µ-
Nano- n-

7. Divide () multiply (×) Converting units using prefixes Giga (G) 1000
Mega (M)
(Unit)
meter(m)
gram(g)
Liter(L)
Second (s)
1000
kilo (k)
1000 10
deci (d) 10
centi (c) 10
multiply (×)
milli (m)
1000
micro ()
1000
nano (n)

8. Examples on converting units using prefixes
1- 3 mm = _________ m
0.003
3  10  10  10
3  1000
0.003
Kg = _________ g
5400
5.4 × 1000
5400
g = _________ g
20  1000  10  10  10
20 

9. Examples on converting units using prefixes
4- 3 m = _________ cm
300
3 × 10 × 10
3 × 100
300
g = _________ kg
0.37
370  1000
0.37
g = ___________ ng
36 × 10 × 10 × 10 × 1000 × 1000
36 ×

10. Examples on converting units using prefixes
mL = _________ L
0.15
150  10  10  10
150  1000
0.15
L = _________ mL
1400
1.4 × 10 × 10 × 10
1.4 × 1000
1400
9- 8 s = ___________ s
8 × 10 × 10 × 10 × 1000
8 ×

11. Examples on converting units using prefixes
Mm = _________ m
0.3 × 1000 × 1000
0.3 ×
kg = _________ Gg
0.002
2000  1000  1000
2000 
0.002

12. Quiz 2 Thursday 06/10/2011 Chapter1 – Section 2 Standards of measurement