Metric System
• based on a base unit that corresponds to
a certain kind of measurement
• Length = meter
• Volume = liter
• Mass = gram
• Density = grams per cm³ or g/cm³
• Prefixes + base units make up the metric
system
– Example:
• Centi + meter = Centimeter
• Kilo + liter = Kiloliter
PNEUMONIC for prefixes
•
•
•
•
•
•
•
King
Henry
Died
Unexpectedly
Drinking
Chocolate
Milk
kilo = km
hecto = h
deca = da
UNIT (BASE)
deci = d
centi = cm
milli, = mm
• PREFIXES are based on powers of 10.
• What?
– each prefix is a step either:
• 10 times larger to the left
or
• 10 times smaller to the right
– examples
• Centimeters are 10 times larger than millimeters (1 step)
1 centimeter = 10 millimeters
• Hectometers are 10 times smaller than kilometers (1 step)
10 hectometers = 1 kilometer
Kilo Hecto Deca
10
1000 100
meter
liter
gram
g/cm³
Deci
1/10
Centi Milli
1/100 1/1000
• The three prefixes that we will
use the most are:
– kilo
– centi
– milli
Base Units
kilo
hecto
deca
meter
gram
liter
deci
centi milli
• each “step” to right,
you MULTIPLY by 10
• Each “step” to the left,
you DIVIDE by 10
Ex.- Right direction to go from a base unit to centi
1 liter = 10 deciliters = 100 centiliters
( 1 x 10 = 10)
=
(10 x 10 = 100)
- Left direction to go from base to kilo
1000 meters = 100 hectometers = 10 decameters = 1 kilometer
(1000 / 10 = 100) = (100 / 10 = 10) = (10 /10= 1)
kilo
hecto
deca
meter
liter
gram
g/cm³
=1
deci
centi
milli
• Movement within the metric system is
done by moving the DECIMAL POINT one
place for each “step” desired
Example to right:
move to right to change from meters to millimeters
1.0 meter = 1000.0 millimeters
Example to left:
move to Left to change from liters to kiloliters
1.0 meters = .001 kilometers
kilo
hecto
deca
meter
liter
gram
g/cm³
deci
centi
milli
If you move to the right in the diagram,
move the decimal to the right, no matter
where you are on the scale
• Convert meters to centimeters
5.0 meters = 500 centimeters
kilo
hecto
deca
meter
liter
gram
g/cm³
deci
centi
milli
• Convert kilometers to meters
.3 kilometers = 300 meters
kilo
hecto
deca
meter
liter
gram
g/cm³
deci
centi
milli
If you move to the left in the diagram,
move the decimal to the left, no
matter where you are on the scale
• Convert from meters to kilometers
4000.0 meters = 4.0 kilometers
kilo
hecto
deca
meter
liter
gram
g/cm³
deci
centi
milli
• Convert centimeters to meters
400.0 centimeters = 4.0 meters
kilo
hecto
deca
meter
liter
gram
g/cm³
deci
centi
milli
Metric System
• Summary
– Base units in the metric system are meter, liter,
gram
– Metric system is based on powers of 10
– For conversions within the metric system, each
“step” is 1 decimal place to the right or left
– Using the diagram below, converting to the right,
moves the decimal to the right and converting to
the left moves the decimal to the left