Metric Measurement
The measurement system used in
science and in most countries of
the world.
Where?
• The Metric system is used in all but three
nations in the entire world. Can you name
the three that don’t?
Most countries have adopted the metric system as their
official system of measurement. There are only three
countries in the world that do not use the metric system
for official measurement. The United States, Burma
(Myanmar) and Liberia all depend on older systems of
measurements. Within these countries, however, the
metric system is often used, especially in scientific and
international contexts.
Source www.ehow/about.com
Why?
It is a better system because it is easier to
use.
It is based on multiples of 10, which is easy
to multiply and divide by.
Example: if a table is 354 centimeters long
that would be equal to 3.54 meters. You
just divide by 100 (or move the decimal
point two places to the left). If a table is
354 inches long you would divide by 36
which would be 9.83.
Distance
• Distance (also called length, width, height,
depth & thickness) is measured in one
direction, point A to point B.
Distance continued…
• The tools used include meter sticks, metric
rulers, and odometers.
This is a meter stick…
…it is a stick and it is a meter long
Distance continued…
The units used are based on the meter.
The common units that we use are the
• meter (m)
• centimeter (cm)
• millimeter (mm)
• kilometer (km)
They are all parts of a meter or are made up of meters
How big are they?
Centi means (1/100) so…
… a centimeter (cm) is 1/100th of a meter
Milli means (1/1000) so…
… a millimeter (mm) is 1/1000th of a meter
Kilo means 1000 so…
,,, a kilometer (km) is 1000 meters
Area
• Area (or surface area) is measured in two
directions.
• It is the measure of how many square
units it takes to cover a surface.
Area continued…
• The tools used include meter sticks and
metric rulers.
Area continued…
• The area measurement process involves
measuring the surface in two directions
and then multiplying these dimensions
(L x W).
Area continued…
• The common units that we use are the
square centimeter (cm2), square meter
(m2) and the square kilometer (km2).
Volume
Volume is the measure of how much
space is taken up by matter in three
dimensions.
Volume continued…
There are three different types of volume
measurement depending on what it is you
are measuring.
•
•
•
Volume of regular shaped solids
Volume of liquids
Volume of irregular shaped solids
Volume continued…
Volume of regular shaped solids…
…is used when you are measuring solid
objects that have regular / consistent
characteristics such as flat sides and right
angles.
There are different
formulas used depending
on which geometric
shape you are measuring.
The most common is for
the rectangular prism
(L x W x H)
4cm x 3cm x 5cm = 60cm3
Volume continued…
Volume of regular shaped solids
The tools used include meter sticks and
metric rulers.
The common units used when measuring the
volume of solids are the cubic centimeter
(cm3), and the cubic meter (m3).
Volume of liquids
This process
involves the use of
a graduated
cylinder. The liquid
is simply poured
into the graduated
cylinder and you
read the graduated
lines on the side to
determine the
Meniscus – curved
volume.
surface of the liquid
Volume continued…
Volume of liquids
The tools used include graduated cylinder.
The common units used when measuring
the volume of liquids are the milliliter (mL)
and the Liter (L).
It is important to understand that
1mL is equal to 1cm3.
e
1mL
used for liquids
=
1cm3
used for solids
Volume
of irregular shaped solids
This is used for solid
objects that do not
have a regular
(measurable) shape.
The objects are
submerged in water
and the amount of
water that is displaced
is measured.
Volume continued…
Volume of irregular
shaped solids.
The common measurement tool used is the
graduated cylinder.
Even though graduated cylinders measure
in milliliters, since a solid is being
measured the units used are cm3.
Lets get
organized with
a chart
Tools
Regular
Shaped
solids
Liquids
Irregular
shaped
Solids
Units
Tools
Regular
Shaped
solids
Liquids
Irregular
shaped
Solids
Meter
Stick
Units
Tools
Regular
Shaped
solids
Liquids
Irregular
shaped
Solids
Meter
Stick
Units
cm3
Tools
Regular
Shaped
solids
Meter
Stick
Liquids
Graduated
Cylinder
Irregular
shaped
Solids
Units
cm3
Tools
Regular
Shaped
solids
Liquids
Irregular
shaped
Solids
Units
Meter
Stick
cm3
Graduated
Cylinder
mL
Tools
Regular
Shaped
solids
Liquids
Irregular
shaped
Solids
Units
Meter
Stick
cm3
Graduated
Cylinder
mL
Graduated
Cylinder
Tools
Regular
Shaped
solids
Liquids
Irregular
shaped
Solids
Units
Meter
Stick
cm3
Graduated
Cylinder
mL
Graduated
Cylinder
cm3
Mass
• Our book defines mass as the amount of
matter in an object.
• It is similar to weight and the two are often
confused.
Mass continued…
To measure mass, a balance is used.
The objects mass is compared to objects whose
mass is known.
Mass continued…
The base unit is the gram.
The common mass units are the milligram (mg),
the gram (g) and the kilogram (kg).
Metric Units
Metric Units
1 kilogram (kg) = 1000 grams (g)
1 gram (g) = 1000 milligrams (mg)
Click the image to
watch a short video
about mass.
Which is larger?
A. 1 kilogram or 1500 grams
C. 12 milligrams or 12 kilograms
B. 1200 milligrams or 1 gram
D. 4 kilograms or 4500 grams
Kilogram Prototype Image - http://en.wikipedia.org/wiki/Kilogram
Measuring Mass
We will be using triple-beam balances
to find the mass of various objects.
The objects are placed on the balance and
then you move the weights on the beams
until you get the lines on the right-side of
the balance to match up.
Once you have balanced the scale, you add up
the amounts on each beam to find the total mass.
What would be the mass of the object measured
in the picture?
_______ + ______ + _______ = ________ g
Top Image: http://www.southwestscales.com/Ohaus_Triple_Beam_750-SO.jpg
Bottom Image: http://www.regentsprep.org/Regents/biology/units/laboratory/graphics/triplebeambalance.jpg
Measuring Mass – Triple-Beam Balance
1st – Place the film canister on the scale.
2nd – Slide the large weight to the right until the arm drops below the
line. Move the rider back one groove. Make sure it “locks” into place.
3rd – Repeat this process with the top weight. When
the arm moves below the line, back it up one groove.
4th – Slide the small
weight on the front
beam until the lines
match up.
5th – Add the amounts on each beam to find the total mass to the nearest tenth of a
gram.
Click here to try an online activity.
Mass - vs. - Weight
Weight is similar to mass…
… but they are not the same thing.
Weight is the measure of how much gravity
is pulling on an object.
If the amount of gravity changes, the weight
of an object changes but the mass stays the
same.
Mass vs. weight continued…
• For example if you were to
compare your weight on
Earth to your weight on
the moon, you would
weigh less on the moon,
but your mass would not
change.
• Also, if you were to go to
deep space, far from any
planet or moon, you would
be “weightless” but you
can never be “mass-less”.
Mass vs. weight continued…
Since weight is
dependent on the
force of gravity,
the unit used when
measuring weight
is the Newton (N).
Weight continued…
The tool used to measure weight is called the
scale.
Scales work by compressing or stretching a spring.
Tools
Mass
Weight
Units
Tools
Mass
Weight
Balance
Units
Tools
Mass
Units
Grams (g)
Balance
Milligrams (mg)
Kilograms (kg)
Weight
Tools
Mass
Units
Grams (g)
Balance
Milligrams (mg)
Kilograms (kg)
Weight
Scale
Tools
Mass
Units
Grams (g)
Balance
Milligrams (mg)
Kilograms (kg)
Weight
Scale
Newtons
Density
Density is described in our text book as “the
amount of matter in a given space” and “the
ratio of the mass of a substance to the
volume of the substance”.
I like to explain it as…
… “how heavy something is for its size”.
Density continued…
The easiest
way to picture it
is if you had
several objects
all the same
size, the
heaviest one is
the most dense.
Even a small piece of lead is pretty heavy so we would say lead is
a dense material.
A piece of Styrofoam is not heavy compared to its size so we say
Styrofoam is a low density material.
Density continued…
To measure the density of a material, you must
measure both the mass and the volume of it.
Measure the mass
Measure to volume
Then you find the ratio of these two
measurements. This is pretty easy, you just
divide the mass by the volume (D = M / V).
Density continued…
Since mass is measured in grams (g),
the volume of solids is measured in cubic
centimeters (cm3) and the volume of liquids is
measured in milliliters (mL)…
…the units will be…
…grams per cubic centimeter (g/cm3) for solids
and…
…grams per milliliter (g/mL) for liquids.
Density continued…
• When scientists were creating the metric
system of measurements they planned
ahead to make sure the volume and mass
systems worked together.
• They decided that one (mL) of water would
have a mass of one (g). This insured that
the density of water would be 1 g/mL.
Density continued…
Any object that floats in water has a density of
less than water (less than 1 g/cm3). Any
substance that sinks in water will have a density
more than water (more than 1 g/cm3).