Transcript Introduction to the Metric System

Introduction to the Metric
System
History
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Created during French Revolution (1790)
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Called Systeme International d’Unitès,
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New system of Weights and Measures
created
or SI - International System of Units
Revised periodically
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by International Bureau of Weight and
Measures
Customary Units of Measurement
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The English System
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a collection of functionally unrelated units
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Difficult to convert from one unit to another
Ex. 1 ft = 12 inches = 0.33 yard = 1/5280 miles
Customary Units
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length - inch, foot, yard, mile
weight/mass - ounce, pound
volume - teaspoon, cup, quart, gallon
temperature - degrees Fahrenheit
time - minutes, hours
Advantages of Using the Metric
System
Universal
 Simple to use
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A few base units make up all
measurements
Advantages of Using the Metric
System
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There is only one unit of measurement for
each type of quantity
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To simplify things, very small and very large
numbers are expressed as multiples of the base
unit.
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Prefixes are used to represent how much smaller or larger
the quantity is compared to the base unit.
Easy to convert from one unit to another
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shift decimal point right
shift decimal point left
Advantages of Using the Metric
System
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Same set of prefixes for all units
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Greek - multiples of the base
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Latin - fractions of the base
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kilo - 1000 × the base
hecto - 100 × the base
deka - 10 × the base
deci - tenths of the base
centi - hundredths of the base
milli - thousandths of the base
Mnemonic: “Kids Have Dropped Over Dead
Converting Metrics.”
Metric Units of Measurement
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Metric Units
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length – meter (m)
weight/mass – gram (g)
volume – liter (L)
temperature - degrees Celsius (°C)
time – seconds (s)
Measurement Unit Conversion
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You can convert between units of
measurement
within the metric system
 between the English system and metric
system
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Unit Conversion
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Let your units do the work for
you by simply memorizing
connections between units.
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Example: How many donuts
are in one dozen?
We say: “Twelve donuts in a
dozen.”
Or: 12 donuts = 1 dozen
donuts
What does any number
divided by itself equal?
ONE!
Unit Conversion
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This fraction is called a unit
factor
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Multiplication by a unit
factor does not change the
amount - only the unit.
Example: How many
donuts are in 3.5 dozen?
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You can probably do this in
your head but try it using the
Factor-Label Method.
Unit Conversion Rules
Start with the given information…
 Then set up your unit factor…
 See that the original unit cancels out…
 Then multiply and divide all numbers…
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Unit Conversion Practice
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Example: Convert 12 gallons to units of
quarts.
Unit Conversion Practice
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Example: Convert 4 ounces to kilograms.
Temperature Conversions
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Conversion Between
Fahrenheit, Celsius, and
Kelvin
 Example:
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Convert 75 ºC to ºF
Convert -10 ºF to ºC
Scientific Notation
What is Scientific Notation?
Scientific notation is a way of expressing
really big numbers or really small
numbers in a more concise form.
 It is most often used in “scientific”
calculations where the analysis must be
very precise.
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Scientific notation consists of two
parts:
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A number between 1 and 10
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A power of 10
N x 10x
Are the following in scientific notation?
To change standard form to
scientific notation…
Place the decimal point so that there is
one non-zero digit to the left of the
decimal point.
 Count the number of decimal places the
decimal point has “moved” from the
original number. This will be the
exponent on the 10.
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Continued…
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If the original number was less than 1,
then the exponent is negative. If the
original number was greater than 1, then
the exponent is positive.
Example 1
Given: 289,800,000
 Use: 2.898 (moved 8 places)
 Answer: 2.898 x 108
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Example 2
Given: 0.000567
 Use: 5.67 (moved 4 places)
 Answer: 5.67 x 10-4
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Practice
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Use the link below to practice converting
standard form to scientific notation.
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Converting to Scientific Notation
To change scientific notation to
standard form…
Simply move the decimal point to the
right for positive exponent 10.
 Move the decimal point to the left for
negative exponent 10.
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(Use zeros to fill in places.)
Example 3
Given: 5.093 x 106
 Answer: 5,093,000 (moved 6 places to
the right)
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Example 4
Given: 1.976 x 10-4
 Answer: 0.0001976 (moved 4 places to
the left)
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Practice
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Use the link below to practice converting
scientific notation to standard form.
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Converting to Standard Form
Now take the quiz to test your
scientific notation skills!
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Click on the link below to take the quiz
and then use the answer key for the
correct answers.
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Quiz
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Answers