Introduction to the Metric System

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Introduction to the Metric System
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History

• Created during French Revolution (1790)
• New system of Weights and Measures created
• Called Systeme International dUnitès,
• or SI - International System of Units
• Revised periodically
• by International Bureau of Weight and Measures

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Customary Units of Measurement

• The English System
• a collection of functionally unrelated units
• Difficult to convert from one unit to another
• Ex. 1 ft 12 inches 0.33 yard 1/5280 miles
• Customary Units
• length - inch, foot, yard, mile
• weight/mass - ounce, pound
• volume - teaspoon, cup, quart, gallon
• temperature - degrees Fahrenheit
• time - minutes, hours

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Advantages of Using the Metric System

• Universal
• Simple to use
• A few base units make up all measurements

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Advantages of Using the Metric System

• There is only one unit of measurement for each
  type of quantity
• To simplify things, very small and very large
  numbers are expressed as multiples of the base
  unit.
• 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
• shift decimal point right
• shift decimal point left

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Advantages of Using the Metric System

• Same set of prefixes for all units
• Greek - multiples of the base
• kilo - 1000 the base
• hecto - 100 the base
• deka - 10 the base
• Latin - fractions of 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.

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Metric Units of Measurement

• Metric Units
• length meter (m)
• weight/mass gram (g)
• volume liter (L)
• temperature - degrees Celsius (C)
• time seconds (s)

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Measurement Unit Conversion

• You can convert between units of measurement
• within the metric system
• between the English system and metric system

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Unit Conversion

• Let your units do the work for you by simply
  memorizing connections between units.
• 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!

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Unit Conversion

• This fraction is called a unit factor
• Multiplication by a unit factor does not change
  the amount - only the unit.
• Example How many donuts are in 3.5 dozen?
• You can probably do this in your head but try it
  using the Factor-Label Method.

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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

• Example Convert 12 gallons to units of quarts.

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Unit Conversion Practice

• Example Convert 4 ounces to kilograms.

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Temperature Conversions

• Conversion Between Fahrenheit, Celsius, and
  Kelvin
• Example
• Convert 75 ºC to ºF
• Convert -10 ºF to ºC

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Scientific Notation
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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

• A number between 1 and 10
• A power of 10
• N x 10x
• Are the following in scientific notation?

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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

• 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.

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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

• Use the link below to practice converting
  standard form to scientific notation.
• Converting to Scientific Notation

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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.
• (Use zeros to fill in places.)

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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

• Use the link below to practice converting
  scientific notation to standard form.
• Converting to Standard Form

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Now take the quiz to test your scientific
notation skills!

• Click on the link below to take the quiz and then
  use the answer key for the correct answers.
• Quiz
• Answers