 An
accurate and consistent system of
measurement is the foundation of a healthy
economy. Without a consistent, honest
system of measurement, World trade would
be thrown into chaos. Throughout history,
buyers and sellers have tried to defraud each
other by inaccurately representing the
quantity of the product exchanged. From
ancient times to the present there has been
a need for measuring things accurately.

1967


Surveyor 3 landed in an ancient crater known as the Sea of
Tranquility and sent back data indicating it would be a
suitable landing site for a manned mission.
July 16, 1969

Neil Armstrong and Edwin Aldrin became the first humans to
set foot on the surface of the Moon.


They traveled over 400,000 kilometers through space and landed
within walking distance of the Voyager 3 craft with only 10
seconds of fuel remaining.
Imagine what would have happened if NASA scientists had
inaccurately measured the thrust of the Saturn V rockets,
the mass of the payload, the distance to the Moon, the
location of the Voyager 3 craft, the gravitational field of
the Moon, the rate of fuel consumption, the speed of the
Apollo 11 craft, the orbit of the Moon around the earth,
the astronauts’ rate of oxygen consumption or the radio
frequency of the communication gear!!
 Built
pyramids by measuring the stones they
cut using body dimensions

Every worker could relate.


Small distances = digits
 the width of a finger
Longer distances = cubit
 the length from the tip of the elbow to the tip of
the middle finger
 1 cubit = 28 digits
 Romans

built roads in paces


1 pace = 2 steps
1000 paces = 1 mile (mil is Latin for 1000)
 Danes

seafaring people wanting to know the depth of
water shipping channels

Fathom = distance from the tip of the middle finger
on one hand to the tip of the middle finger on the
other
 Distances
features



were defined by the King’s body
Yard = circumference of his waist
Inch = distance between the knuckles of his thumb
Foot = length of his foot

Acre: The amount of land your ox could plow from
sunrise to sunset.

Hand: King Henry VIII said that it is equal to 4
inches.

What is it used to measure today?
 The height of horses!!!
 Because
every person’s body is different,
using body parts as reference would cause
every measurement to be inaccurate.

As various cultures emigrated to England, they
brought with them various measurement systems.
Today, the English or Customary system reflects the
variety of different measurement systems from which
they originated.

There are, for example many units in which distance
can be measured in the Customary system, but bear
no logical relationship to each other.
1 statue mile = 0.8688 nautical miles = 1760 yards = 320 rods =
8 furlongs = 5280 feet = 63,360 inches = 880 fathoms = 15,840 hands

Unfortunately, most people have no idea what
nautical miles, fathoms, hands, or furlongs are
because they use only the more common measures of
miles, yards, and inches.
 What
is a better price for
gasoline?


Canada: $2.98/liter
U.S.:
$3.59/gal
 Therefore,
we need a system that
everyone uses!!!!!!!!!!!

1670


measurement system based on the decimal system
proposed.
1791

metric system developed (metric is based on the French
word for measure.)


Prefixes were agreed upon
 Multipliers >10 = Greek
 Multipliers <10 = Latin
1960


an international conference was called to standardize the
metric system.
Scientists developed “Le Système Internationale d’Unités”
more commonly known as the SI System.





It is the modern version of the metric system
Base 10
Simple
Used by scientists worldwide
Mandatory system of measurement in every country
of the world except the U.S., Liberia, and Burma
BASE UNIT
QUANTITY
SYMBOL
meter
length
m
*kilogram
mass
kg
second
time
s
Kelvin
thermodynamic
temperature
K
mole
amount of substance
mol
ampere
electric current
A

1 meter = 0.001 kilometers = 1000 millimeters =
1,000,000 micrometers = 1,000,000,000 nanometers
 The
meter was originally intended to be
1/10,000,000 of the earth’s meridian that passes
through Paris. It is now defined as the distance
light travels in 1/299,792,458 of a second.
 The
kilogram is the only SI base unit to
incorporate a prefix.
 The
kilogram is the only unit still based on a
single lump of stuff. All the other
definitions can be reproduced with a high
degree of accuracy in any laboratory with
the proper equipment.
16 prefixes (NEED TO MEMORIZE 10)
PREFIX
Symbol
Examples
using
prefixes
giga-
G
Gg, Gm, Gs
1000000000 g = 1 Gg
109
mega-
M
Mg, Mm, Ms
1000000 g = 1 Mg
106
kilo-
k
kg, km, ks
1000 g = 1 kg
103
deka-
da
dag, dam, das
10 g = 1 dag
101
BASE UNIT
BASE UNIT
BASE UNIT
BASE UNIT
100
deci-
d
dm, dg
10 dg = 1g
10-1
centi-
c
cm, cg
100 cg = 1g
10-2
milli-
m
mm, mg, ms
1000 mg = 1g
10-3
micro-

g, m, s
1000000 g = 1g
10-6
nano-
n
ng, nm, ns
1000000000 ng = 1g
10-9
pico-
p
pg, pm, ps
1000000000000 pg = 1 g
10-12
Meaning
Exponential
Notation
millimeter, centimeter
microsecond, second
kilogram,
kilogram centigram
deciliter milliliter
deciliter,
picometer, nanometer
megaliter dekaliter
megaliter,
Give the name of each of the following quantities.
millimeter
________________________

0.001 m

microsecond
0.000001 s ________________________

0.01 g
centigram
________________________

1000 m
kilometer
_______________________

picoliter
0.000000000001 L _________________

megamole
1000000 mole______________________
 10-2 pedes
 106 phones
 101 cards
 10-12 boos
 10-6 phones