Meters (m), Grams (g), Liters (l),
and degrees Celsius (°C)
The Metric System
• The metric system is a measurement
system based on our decimal (base 10)
number system.
• Other countries and all scientists and
engineers use the metric system for
measurement.
• We’re going to start by becoming familiar
with the basic metric units of measure.
Basic unit of temperature:
degrees Celsius (°C)
• Temperature scales used
in science are typically
either Celsius or Kelvin.
• In science class we will
be using Celsius.
• Note: thermometers will
have both Fahrenheit and
Celsius. Make sure you’re
reading the correct scale
when collecting data.
Basic unit of length or distance:
meter (m)
• Meters measure
length or distance
• Commonly used units
include:
– Millimeter (mm)
– Centimeter (cm)
– Kilometer (km)
(This would be a little less than 45 mph.)
Meters
• One millimeter is
about the thickness of
a dime.
Meters
• One centimeter is
about the width of a
large paper clip
•or the average pinky fingernail.
Meters
• A meter is about the width of a doorway
Meters
• A kilometer is about six city blocks or 10
football fields.
• 1.6 kilometers is about 1 mile
Tools to measure metric length
or distance in science
• Metric ruler
• There are 10 millimeters (mm) in every
centimeter (cm)
Tools to measure metric length
or distance in science
• Meter stick –
NOT a
yardstick.
• There are 100
centimeters
(cm) in a
meter (m).
No
Yes
Basic unit of volume:
liter (l) or (L)
• Volume is the amount of
space that a substance
or object occupies, or
that is enclosed within a
container.
• Liters measure liquid
volume.
• Commonly used units
include:
– Milliliter (mL)
– Kiloliter (kL)
Liters
• 1 milliliter is about the
amount of one drop
Liters
• 1 liter is half of a
2-liter bottle of
Coke or other
soda
Liters
• A kiloliter would be
about 500 2-liter
bottles of pop
Tools and methods to measure
metric volume in science
• Graduated Cylinder
Tools and methods to measure
metric volume in science
• To measure liquid
volume, look at the
surface of the liquid in
the graduated cylinder.
The curved line at the
top of the liquid is called
the meniscus.
• Always read the bottom
of the curve for accuracy.
Tools and methods to measure
metric volume in science
• What if you wanted
to measure a solid
object?
• If it’s a regular
object, you can just
use a formula, such
as:
Length x width x height
Tools and methods to measure
metric volume in science
• If you want to measure the
volume of an irregular
solid object, you can use
the displacement
method.
Tools and methods to measure
metric volume in science
• Put water in a beaker or
graduated cylinder and
measure the volume.
• Then place the irregular
solid object into the water
and measure the volume
again.
Tools and methods to measure
metric volume in science
• The difference between
the measurement before
and after you added the
object is the volume of
the object.
• Again, always read the
bottom of the meniscus
curve for accuracy.
Basic unit of mass:
gram (g)
• Mass is a measure of how
much matter is in an object.
• Not the same as weight.
Weight is the measure of
gravitational pull on an object.
• Grams are used to measure
mass of an object.
• Commonly used units include:
– Milligram (mg)
– Kilogram (kg)
Grams
• A milligram has about
as much mass as a
coarse grain of salt.
Grams
• 1 gram weighs about
as much as a small
paper clip.
• 1 kilogram weighs
about as much as 6
apples or 2 pounds.
Tool to measure metric mass in
science:
• Triple beam balance, also called a gram scale
• You can practice using a triple beam balance
virtually at:
http://www.ohaus.com/input/tutorials/tbb/TBBread.html
Metric Prefixes
• A prefix is a group of letters added to the beginning of a
word that modifies, or changes the meaning of, that word.
The metric system has prefix modifiers that stand for
multiples of 10.
• By adding a metric prefix to one of the base units (meter,
liter, or gram), you change the value of that unit.
• Example 1: The distance (value) of the base unit meter is
1 meter. But if you add the prefix kilo- to the base unit
meter, you now have the unit kilometer. The distance
(value) of a kilometer is 1000 meters.
• Example 2: The distance (value) of the base unit meter is
1 meter. But if you add the prefix centi- to the base unit
meter, you now have the unit centimeter. The distance
(value) of a centimeter is 1/100th of a meter, or .01 meters.
Metric Prefixes
• Good mnemonic device to memorize the prefixes in order:
King Henry doesn’t usually drink chocolate milk
Prefix Symbol
Factor Number Factor Word
Kilo-
k
1000
Thousand
HectoDecaUnit
DeciCentiMilli-
h
da or dk
m, l, or g
d
c
m
100
10
1
.1
.01
.001
Hundred
Ten
One
Tenth
Hundredth
thousandth
Converting Metric Units
• To convert from one unit to another in the
metric system you simply move the
decimal point to the left or right as needed.
• An easy way to do this is to use the Metric
Conversion table.
Converting Metric Units
Place Values of Metric Prefixes
To change from a larger unit
to a smaller unit, move the
decimal point to the right.
dm
dL
dg
cm
cL
cg
Thousandth
m
L
g
Hundredth
Tenth
dkm
dkL
dkg
One
hm
hL
hg
Ten
Hundred
Thousand
km
kL
kg
mm
mL
mg
Place Values of Metric Prefixes
To change from smaller
units to larger units, move
the decimal point to the left.
dm
dL
dg
cm
cL
cg
Thousandth
m
L
g
Hundredth
Tenth
dkm
dkL
dkg
One
hm
hL
hg
Ten
Hundred
Thousand
km
kL
kg
mm
mL
mg
Which unit would you use to
measure the length of this bicycle?
km
m
cm
mm
Which unit would you use to
measure the mass of a penny?
km
g
cL
mg
Which unit would you use to
measure the water in an aquarium?
L
m
cL
mg
Which unit would you use to
measure the mass of a feather?
L
m
cL
mg
Which unit would you use to
measure the mass of a student
desk?
kg
g
cL
mg
Which unit would you use to
measure the mass of a whole
watermelon?
kg
g
cL
mg
Which unit would you use to
measure the mass of an egg?
kg
g
mm
mg
Which unit would you use to
measure a can of soup?
kL
L
mm
mL
Which unit would you use to
measure this glass of milk?
kL
L
cL
mL
Which unit would you use to
measure the distance across
Kansas?
km
m
cm
mL
Which unit would you use to
measure the height of a tree?
km
m
cm
mm
Which unit would you use to
measure the length of a bracelet?
km
m
cm
mm
Sorry!
• That is not the BEST choice!