Transcript The Metric System

THE HISTORY OF
MEASUREMENT
Where did the metric system
come from and what are its
base units?
EARLY MEASUREMENT
The earliest types of measurement
were based on body parts,
objects found in nature, or
human activities.
FOR EXAMPLE , ANCIENT PEOPLE
USED THEIR HANDS OR HOW FAR
THEY COULD WALK IN ONE DAY TO
MEASURE DISTANCE.
OR THEY USED ROCKS TO
FIGURE OUT HOW MUCH
SOMETHING WEIGHED.
OR THEY MEASURED AREA BY HOW
MUCH LAND A PERSON COULD
PLOW IN ONE DAY.
BUT THIS CREATED
PROBLEMS!
There was no STANDARD for
measuring. Without a STANDARD
people couldn’t agree on exactly
what they were measuring. For
example, if you said you wanted to
trade 5 ROCKS of grain for 50
HANDS of cloth, how much you
gave and got in return depended on
whose HAND you used and how big
the ROCKS were!
CIVILIZATIONS CREATED
STANDARDS
The early Babylonians designed a
system based on the GUR – the
biggest box of water the king’s
ass could carry.
EGYPTIANS
The EGYPTIANS used the royal
CUBIT, which was the length from
pharaoh's elbow to his middle finger
tip. One CUBIT was equal to 7
PALMS or 28 FINGERS.
GREEKS AND ROMANS
The Greeks and Romans use the size
of a “normal” soldier’s FOOT. That
soldier’s PACE was equal to 5 FEET
and a mile was 1000 PACES.
THE ENGLISH SYSTEM
In the early 1100’s an
English King tried to
standardize
measurement again. He
used HIS foot and divided
it into 12 inches (each
about the width of his
thumb.) One YARD
became the distance from
the tip of his nose to the
tip of his fingers.
IT’S ALL STILL VERY
CONFUSING, BUT IT’S
STANDARDIZED!
1
inch is the width of the King’s thumb
 1 foot is the length of the King’s foot
 1 yard is the distance from his nose to his
fingers
 1 rod is equal to 20 feet
 1 furlong is the length of a standard
furrow and equals 40 rods
 1 mile equals 8 furlongs, of 5280 feet
HOW’S ABOUT TEMPERATURE
MEASUREMENT?
In 1724 Daniel
Fahrenheit came up
with our system for
measuring
temperature. He made
0˚ the temperature at
which water froze
when it was saturated
with ammonium
chloride.
SO WHY DOES PURE WATER
FREEZE AT 32˚ AND BOIL AT
212˚?
He wanted his thermometer to be easy to
make, so he set it that pure water froze at
32˚ - which was 2 x2x2x2 degrees above
his 0˚
He then said that the body’s temperature
was 2x2x2x2x2 degrees higher than
freezing – or 96˚,
When he used those size degrees, water
ended up boiling at 212˚
Simple, right?! $#%@$^&
THE FRENCH REVOLUTION!
In 1789 the French
revolted and overthrew
their monarchy. When
they got rid of their
king, they also wanted
to get rid of everything
that was connected to
the king (like his
HEAD!)
They wanted a new system of
measurement that was
SCIENTIFIC, UNIVERSAL, and
EASY to use.
The first step was to base all
measurement on the number 10.
Makes for simple multiplication
and conversion to different size
units.
LENGTH
Started with a new unit for
length. The METER! Defined 1
meter as equal to 1/10,000,000th
distance from North Pole to
equator going through Paris.
GOING SMALLER
To make smaller units, they divided
the METER into 100 equal pieces.
Each piece became a
CENTIMETERS. For even smaller
measurements, they divided each
centimeter into tenths and got
MILLIMETERS.
WHAT ABOUT VOLUME?
They started out by making a small
cube that is one centimeter on a side
– ONE CUBIC CENTIMETER!
1 cm
1 cm
1 cm
TOO SMALL!!
One cubic centimeter is pretty
darn small. It’s about the
size of a sugar cube. That’s
too small to use as a basic
unit of volume.
THE LITER
They solve that problem by
making a BIGGER box for
their standard unit for
volume. The new box was
10 centimeters on a side
and was called a LITER.
Each LITER has 1000
CUBIC CENTIMETERS
in it.
HOW DID THEY HANDLE MASS?
The basic unit for mass in the
metric system is the GRAM.
The French came up with the
GRAM by making it equal to the
mass of one cubic centimeter of
water.
QUESTION!!
If one cubic centimeter
of water has a mass
of one gram, what is
the mass of a liter of
water?
LAST BUT NOT LEAST
Let’s
Talk
Temperature!
CELSIUS
TEMPERATURES
Pure water
freezes at
0˚ C and
boils at
100˚C.
SOOOO . .
That’s how we got the
basic units for the
metric system!
Now let’s talk about the
prefixes and metric
conversions.