THE METRIC or INTERNATIONAL SYSTEM of MEASUREMENT SI

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THE METRICorINTERNATIONAL SYSTEM of MEASUREMENT
(SI)
Scientists all over the world need to
communicate with each other. To
do this easily, they use the same system of
measurement. This
system is known as the
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THE BASIC UNIT OF THE ENTIRE SI SYSTEM IS THE
METER

• This fundamental unit is a bit longer than a
  yard.

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HOW TO MAKE LINEAR MEASUREMENTSUSING SI UNITS
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• To measure SMALLER distances, the METER is
  divided by a factor of 10
• EXAMPLES
• Decimeter (dm) 1/10 of a meter
• Centimeter (cm) 1/100 of a meter
• Millimeter (mm) 1/1000 of a meter

A 3 day old tadpole is 1.2 centimeters in
length.
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• To measure LARGER distances, the METER is
  multiplied by a factor of 10
• EXAMPLES
• Hectometer (hm) 100 meters
• Kilometer (km) 1000 meters

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THE BASIC UNITS USED FOR MOST LINEAR MEASUREMENT
ARE THESE FOUR
MILLIMETERS - very small measurements CENTIMETERS
- small measurements METERS - large
measurements KILOMETERS - very large measurements
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SI units should NOT be MIXED.
That is, you would not write 1 meter 21
centimeters.You should write 1.21 meters.
Also, linear measurements should be written using
DECIMALS. In most linear measurements, ONE
DECIMAL PLACE is sufficient. Do NOT use
FRACTIONS!
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ONE LITER
To obtain a unit of VOLUME in the SI System,
scientists took a empty box
that measured 10 cm. by 10 cm. by 10 cm. and
called this
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A LITER is now a common unit used by all of us.
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A LITER is also used with the prefix MILLI.
Thus we have
a MILLILITER to measure very small volumes.

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This is a ONE LITER cube. 1/1000 th of it is
1 MILLILITER.
This small cube is one milliliter.
This large cube is one liter.
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A MILLILITER has the same volume as
ONE CUBIC CENTIMETER.
125 ccs
Which means, milliliters (ml) and cubic
centimeters (cc) can be interchanged.
They both have the SAME volume!
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Nowto get a unit for MASS, scientists took
1 MILLILITER OF WATER and made
that mass equal to 1 GRAM!
1 ml of water 1 gram
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Again, PREFIXES can be used in front of a
GRAM.The common ones are
MILLIGRAM - very small masses KILOGRAM - large
masses
1 carat equals 200 milligrams
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Before we leave MASS units, we need to consider
one other thing
MASS and WEIGHT are NOT the same!
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MASS is the amount of stuff in an object.
It does NOT have
anything to do with GRAVITY!
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MASS does NOT change !It is measured in
GRAMS.Its the SAME everywhere in the
universe.It does NOT depend on gravity.It is
measured with a BALANCE.
All these things masses stay the same, wherever
they are!
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WEIGHT CHANGES !It depends on GRAVITY.It is
usually measured in pounds.It is measured with
a spring scale.
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WEIGHT CHANGES WITH GRAVITY!
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You may be WEIGHTLESS but you still have MASS!
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and finallyTHERE TWO TYPES OF MEASUREMENT IN
SCIENCE
QUANTITATIVE
QUALITATIVE
YOU WEIGH 100 POUNDS.
AN UGLY BABY?
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1. QUANTITATIVE

• EXAMPLES
• 70 degrees Celsius
• One inch of rain
• 6.2 centimeters
• 640 miles
• She scored 26 points

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MAKING QUANTATIVE MEASUREMENTS
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2. QUALITATIVE

• EXAMPLES
• Its nice out
• Its really hot
• Its raining cats and dogs
• Hes good looking

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Whenever possible
QUANTITATIVE is preferred over
QUALITATIVE in SCIENCE!
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A QUICK SI REVIEW

• 1. THE BASIC SI UNIT OF LENGTH IS A _____.
• 2. 1/100th OF A METER IS _____.
• 3. THE SI SYSTEM USED TO BE CALLED _____.
• 4. A ____ IS USED TO MEASURE VERY LARGE
  LINEAR DISTANCES.
• 5. 1/1000th OF A GRAM IS ONE _____.
• 6. AREA IS FOUND BY MULTIPLYING _____.
  TIMES THE _____.
• 7. THE BASIC SI UNIT OF MASS IS A _____.
• 8. THE SMALLEST SI PREFIX USED DAILY IS THE
  _____.
• 9. WEIGHT CHANGES WITH ______.
• 10. THE BASIC SI UNIT OF VOLUME IS A ______.