The Metric System
Measurement
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What unit would you use to measure…
the length of the classroom?
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How much water fits in a bathtub?
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How much you weigh?
English System
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Liquid ______________________
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Mass ______________________
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Length ______________________
Metric System Basics
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In science class, we will be using the Metric
System. Most countries only use the metric
system.
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Allows scientists to compare data and
communicate with each other
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Standardized system based on the number 10
Metric System Basics
In the metric system, we will be using the
following terms: Grams, Liters, and
Meter
Can you guess which one is used for:
Length: _________________
Mass:___________________
Volume:_________________
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The Meter
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The basic unit of length in the metric system in the
meter and is represented by a lowercase m.
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There are other units length is measured in as well:
the Kilometer (km) and the Millimeter (mm)
Metric Units of Length
Metric Units

1 Kilometer (km) = 1000 meters
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1 Meter = 100 Centimeters (cm)
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1 Meter = 1000 Millimeters (mm)
The Meter Stick
How many millimeters are in 1 centimeter?
 1 centimeter = 10 millimeters
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The Meter Stick
What is the length of the line in centimeters? _______cm
What is the length of the line in millimeters? _______mm
What is the length of the line to the nearest centimeter? ________cm
Volume!!
Volume= how much space an object takes
up
 The metric system uses the Liter (L)

There are other units of volume as well: the
Milliliter (mL)
1 liter (L) = 1000 milliliters (mL)
Volume

Volume is used to measure liquids and
solids

How would you measure the volume of
liquid?
Volume
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We will be using graduated cylinders to find the volume of liquids and other
objects
Volume
Read the measurement based on the bottom of
the meniscus or curve. When using a real
cylinder, make sure you are eye-level with the
level of the water.
What is the volume of water in the cylinder?
_____mL
What causes the meniscus?
A concave meniscus occurs when the molecules of the liquid
attract those of the container. The glass attracts the water on
the sides.
What is the volume of water in each cylinder?
Volume
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How would you measure the volume of a solid?
9 cm
Length x width x height
8 cm
10 cm
__________ X ____________ X ___________ =
Volume
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How would you measure the volume of an
irregular solid?
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Water Displacement!!!

Amount of H2O with object = ______
About of H2O without object = ______
Difference = Volume = ______
Mass
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Definition: the amount of matter an object
contains
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The metric system uses the gram (g)
The other metrics units used are the:
 Kilogram (kg) and the Milligram (mg)

Mass
Metric Units
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1 Kilogram (km) = 1000 Grams (g)
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1 Gram (g) = 1000 Milligrams (mg)
Measuring Mass
We will be using triple-beam balances
to find the mass of various objects.
The objects are placed on the scale and
then you move the weights on the beams
until you get the lines on the right-side of
the scale 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.
Just Checking…
What is the basic metric unit for length?
 How many millimeters are in a centimeter?
 How many centimeters are in a meter?
 How many meters are in a kilometer?
 What is volume?
 What is the basic metric unit for volume?
 What does a graduated cylinder measure?
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Just Checking…
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If you wanted to measure exactly 25.6 mL of liquid, what
would you use to measure with?
Which is larger, a milliliter or a Liter?
If you wanted to measure about 100 mL of water, what
would you use to measure with?
How many mL are in one Liter?
What is the formula for measuring the volume of a
regular solid?
How would you find the volume of a round object?
Density
 Definition:
is a comparison of
how much matter there is in a
certain amount of space
Density

How about this: Which square is more
dense? Why?
Density…
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Can two objects have the same volume but
different densities??
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Yes!
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Can anyone think of any objects that are similar
in volume but have different densities?
Density
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Can two objects have the same mass but
different volumes?
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Yes!!
Calculating Density…
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Density is measured with two metric units:
volume AND mass

Density = object’s mass/object’s volume
Units
of density= g/mL
Or g/cm^3
Let’s Try a Density Problem…
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Frank has a paper clip. It has a mass of 9g
and a volume of 3cm3. What is its density?
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Frank also has an eraser. It has a mass of
3g, and a volume of 1cm3. What is its
density?
Work On These With Your
Partner
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Ms. Lasee has a rock. The rock has a
mass of 6g and a volume of 3cm3. What is
the density of the rock?
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Ms. Frantz has a gel pen. The gel pen has
a mass of 8g and a volume of 2cm3. What
is the density of the pen?
Try These On Your Own
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Allura has a watch. It has a mass of 4g
and a volume of 2cm3. What is the density
of the watch?
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Thomas has a wallet. It has a mass of 15g
and a volume of 5cm3. What is the density
of the wallet?
Floating vs. Sinking
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Think back to the floating egg experiment…Why
did the egg float? Why did the egg sink?
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Objects less dense than water will float
Objects denser than water will sink
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Density of water=1.0 gram/cm^3
 Objects
with density LESS THAN 1.0g/cm^3 =float
 Objects with density MORE THAN 1.0g/cm^3 =sink