Metric History

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Metric History
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Metric System
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Confusing Measurements
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French National Assembly Academy of Sciences
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Metric System

• Insured worldwide standard

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Quadrant Surveyors
PFA Mechain
JBJ Delambre
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Measuring the Quadrant
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Early Researchers
J.R. Benoit
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Excited Cadmium Atoms Wavelength
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Defined By Light
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Meter Stick

• 1 meter 3.28 feet

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mm And cm
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Prefixes
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Prefixes

• Metric Prefixes can be used with any base unit.

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Metric Prefixes
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Teaching Prefixes
Learn the 16 regular prefixes by counting Change
them by jumping the decimal point 3 places Dont
call this converting units Set calculator
display to ENG Avoid the irregular prefixes (h,
da, d, c) except in cm, cm2, cm3, dm3, hm2, hm3
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Advantages of Metrics
No conversions No fractions No numbers to
memorize No awkward rows of zeroes Complete Cohere
nt Unambiguous symbols Only 30 units The world
standard
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• The meter is the length of the path travelled by
  light in a vacuum during a time interval of 1/299
  792 458 of a second. (1983)