With a partner, try to complete the following conversions of
our wonderful (??) English measurement system:
1760
1 mile = ____________
yards
3
1 yard = ____________
feet
36
1 yard = ____________
inches
12
1 foot = ____________
inches
16
1 pound = ____________
ounces
8
1 cup = ____________
ounces
16
1 cup = ____________
tablespoons
3
1 tablespoon = ____________
teaspoons
32
Water freezes at ____________°F
212
Water boils at ____________°F
With a partner, try to complete the following conversions of
the metric (SI) system:
1000
1 km= ____________
m
100
1 m= ____________
cm
10
1 cm= ____________
mm
1000
1 kg= ____________
g
1000
1 L= ____________
mL
1
1 mL= ____________
cm3
0
Water freezes at ____________°C
100
Water boils at ____________°C
English vs. Metric
• Which of the two systems of measurement
were the easiest to use?
• Why don’t you think that the United States
hasn’t switched to the metric system like
much of the rest of the world?
The Standard Metric Units
• The metric system is also referred to as the
“International System” of units or SI (Standard
International) Units
• The standard units of measurement that are
used in the metric system are:
•
•
•
•
For length: meter (m)
For mass: kilogram (kg)
For time: seconds (s)
For temperature: kelvin (K)
• Add 273.15 ° to °C to get K
Prefix multipliers
• The SI system uses prefix multipliers with the
standard units of measurement (m,kg,s)
• These multipliers change the value of the unit
by a power of 10 (Table 2.2, p. 23)
– i.e. kilo means 1000 or 103 so 1 kilometer = 1000 meters
Prefix multipliers
hecto
h 100
102
deka da 10
101
Prefix
Symbol
Multiplier
tera
T
G
M
K
1,000,000,000,000
1,000,000,000
1,000,000
1,000
Exponential
Form
1012
109
106
103
m
g
s
1
100
d
c
m

n
p
f
0.1
0.01
0.001
0.000001
0.000000001
0.000000000001
0.0000000000000
01
10-1
10-2
10-3
10-6
10-9
10-12
10-15
giga
mega
kilo
Base:
Meters
Grams
Seconds
deci
centi
milli
micro
nano
pico
femto
kilo
1000 units
103
hecto
100 units
102
deka
10 units
101
deci
.1 units
10-1
centi
.01 units
10-2
milli
.001 units
10-3
24 grams
Convert to kilograms: Move decimal 3 place to the left
Or take 24g / 103
= .024 kg
Convert to milligrams: Move decimal 3 place to the right
Or take 24g x 103
= 24,000 mg
Practice
• Convert 2,156 g to the following units:
– kg
– Mg
– mg
– cg
2.156 kg
0.002156 Mg
2,156,000 mg
215,600 cg
Derived Units
• Volume: Units of length to the 3rd power
become volume (cm3, m3)
– length x width x height
– water displacement
• We will commonly use liters to measure
volume
• 1 mL = 1 cm3
• 1 L = 1000 mL = 1000 cm3
Derived Units
• Density: the amount of “stuff” crammed into
something (a ratio of its mass to volume)
density = mass
volume
***This formula can also help you
figure out mass and volume when
given the other values
Volume/Density Practice
• What is the volume of a cube that has a width
of 2.5 cm?
15.6 cm3
– How many mL would that be? 15.6 mL
• If the cube has a mass of 52.3 g, what is the
cube’s density?
d=m/v
d = 52.3g / 15.6 cm3 = 3.35 g/cm3
• If a copper penny has a density of 8.92 g/mL
and a mass of 2.81 g, what is it’s volume?
V=m/d
V = 2.81g / 8.92 g/mL = 0.315 mL