High School SMILE Meeting
1997-98 -- 05-06 Academic Years
The Metric System
|
15 September 1998: Ann Brandon [Joliet West HS]
She brought in labels from a soda bottle sold in Australia. They
indicated not
calories, or even kilo-calories, but kilo-Joules. It was commented by
the
audience that Calories are a nice even standard 1-11 versus "some-thing
that is not an even integer"
01 May 2001 Lee Slick (Morgan Park HS) Handout: English
Units (only for non-metric die-hards!)
gave the following information about English units in excruciating detail:
Distance
| 1 league = 3 miles |
1 nautical mile = 1.154 miles |
1 Roman mile = 0.949 miles |
| 1 mile = 8 furlongs |
1 furlong = 10 chains |
1 chain = 4 rods |
| 1 mile = 5280 feet |
1 foot = 12 inches |
1 cubit = 18 inches |
Volume
| 2 mouthfuls = 1 jigger |
2 jills = 1 cup |
2 quarts = 1 pottle |
2 pails = 1 peck |
| 2 jiggers = 1 jack |
2 cups = 1 pint |
2 pottles = 1 gallon |
2 pecks = 1 bushel |
| 2 jacks = 1 jill |
2 pints = 1 quart |
2 gallons = 1 pail |
... etc ... |
20 September 2005: Ann Brandon (Joliet Central HS physics,
retired)
Testing the Royal Inch
Ann recently visited American Science and Surplus, and
called our
attention to their 20% off Teachers' Appreciation Day sale,
Saturday, September 24. She
earlier had bought a Vernier caliper
with an electronic digital display there. She had each of us use it to
measure the distance from the first to the second
knuckle in our left index fingers to see how close our class was to
this classical definition
of an inch. We obtained the
following set of 24 measurements, in millimeters,
arranged in decreasing
magnitude:
| 33.6 |
33.0 |
32.6 |
31.9 |
| 31.9 |
31.7 |
31.1 |
30.4 |
| 30.4 |
30.2 |
30.1 |
30.1 |
| 29.9 |
29.9 |
29.8 |
29.6 |
| 29.4 |
29.4 |
29.3 |
29.2 |
| 28.7 |
28.5 |
28.0 |
26.9 |
The average is 30.3 mm, with a range of 26.9 mm - 33.6 mm.
When the largest and smallest four values were removed from the
data, the range is from 29.2 mm to 31.9 mm. Using
half of this range
to estimate the standard deviation, we get 1.4 mm; in other
words 30.3 ± 1.4 mm. One
inch is
25.4 mm, so we seem to be about 20% larger than the medieval
measure. For details see the web page Anglo-Saxon Weights and
Measures:
http://users.aol.com/jackproot/met/spvolas.html
and Medieval Weights and Measures: http://www.answers.com/topic/medieval-weights-and-measures.
13 December 2005:
Marva Anyanwu [Wendell Green School,
science]
Teaching the Metric System
Marva asked us to write down in proper format the expressions
for three hundred
millimeters [300 mm] and thirty-six kilograms [36 kg]
on a sheet.
Then she gave us each a list of eight questions to answer, as well as
an answer
sheet. Here are the questions and answers about the metric system [http://lamar.colostate.edu/~hillger/#metric]:
-
Q: What is the official name of the modern metric system and
what is its
abbreviation?
A: The official name is International System of Units. Its
abbreviation is
SI (Système Internationale d'Unités).
- Q: How many basic units are there in the metric system?
What are they?
A: The metric system consists of seven base units: meter
(m), kilogram (kg),
second (s), Kelvin (K), Ampère (A), mole (mol), and candela
(cd).
- Q: Which metric units are preferred for expressing
clothing and body units?
A: The centimeter (cm) is preferred for measuring clothing
and body measurements.
- Q: What is the difference between temperatures in degrees
Celsius and Kelvin?
A: The degree Celsius is meant for ordinary temperatures
(with 0oC as
the freezing temperature of water and 100 oC as the boiling
temperature of water at sea level). The Kelvin scale is a scientific
scale
for temperatures above absolute zero ( 0 K is about - 273 oC).
- Q: Which is larger, a quart or a liter ... and how many
milliliters large is it?
A: A liter is larger than a quart. It contains 54
milliliters (mL ) more than a quart.
A liter contains 1000 mL. A quart contains 946 ml.
- Q: Which metric system prefix means one-millionth?
A: The metric system prefix for one-millionth is micro.
- Q: What is the difference between mass and weight?
A: Mass is the quantity of matter, measured in kilograms
(kg). In everyday language,
mass is usually called "weight", as in "my weight is 68 kg" or "I weigh
68 kg".
However, in correct scientific language, the word weight is reserved
for the force
of gravity, which is measured in Newtons (N). [It is more correct,
technically,
to state "my mass is 68 kg". However, in everyday life, the word
"weight" is used.]
- Q: What are the short forms for metric units called?
A: The short forms for metric units are called symbols. [It
is not correct to
call them abbreviations.]
We discussed the questions and answers for a few minutes. Porter
made
these comments about everyday life in a metric country, based upon his
two years
of experience living in The Netherlands in the 1970s and 1980s:
- The essence of the "metric system" is a set of units
separated by factors of ten, rather than the more primitive units based
upon separations by factors 2, 4, 12, and 20. In 1789 the newly
formed
United States of America was the first large nation in the world that
adopted "base ten
money" based upon "dollars and cents", rather than "pounds, shillings,
and pence". The
Napoleonic monetary system of "francs and centimes" was a copy of ours.
Napoleon
also developed a base ten metric system of units --- he even
experimented with "base 10
time units -- 100 days per year", but that idea was quickly found
to be impractical, and we still have "base 24 and base 60"
primitive time units. [Except for Swatch Time -- for details
see the Swatch Internet Time website: http://en.wikipedia.org/wiki/Swatch_Internet_Time.]
The base-10
English system of units was adopted in the United Kingdom after the
defeat of Napoleon.
The English unit system was a "parallel version" of the Napoleonic
system, based upon the
foot, pound, and second. The "standard pound" and "standard foot" were
located in
Greenwich (London environs), whereas the "standard kilogram and meter"
were located
in Paris for over two centuries.
- One real advantage to a more primitive unit system is that it is
easier to split things into halves, thirds and quarters than in a
metric unit system. North Americans living
in continental Europe very quickly realize that they get ten eggs in a
carton or a
ten-pack of beverages. What can a chef do with only 10 eggs,
with three, four, or six per serving?
- The average European is no more scientifically literate than the
average North
American. The green grocer will have no understanding of the
distinction between mass versus weight. S/he will know nothing about
English units, and cannot possibly convert back and forth. In a
purely metric country, conversion simply involves multiplying and
dividing by factors of 10. European Ounces (actually, 100
grams) and pounds (actually, 500 grams) are very commonly
used in commerce.
- In Germany the beverage glasses must be marked in cl
(centiliters) or dl (deciliters). For example, 0,5
dl (Eur) or 0.5 dL (USA) means 5 deciliters, or a half-liter.
By law the glass must be filled to that mark with beverage, not
counting foam!
- European clothing sizes, while based on the metric system, are no
more rational
than those in the USA -- and certainly not simpler to use! Ladies
unmentionables
are purchased in sizes 75 - 80 - 85 - 90. These numbers, which
refer to centimeters,
correspond approximately to 30 - 32 - 34 - 36 inches. However,
it is pointless to
convert them from metric to English units, since they are defined in
terms of a different
torso measurement. A similar story goes for all clothing --- try
it on to be sure
that it will fit you!
- American shoe sizes 9 - 10 - 11 refer directly to foot
length in inches, whereas
European shoe sizes 41 - 45 are defined more indirectly.
Caveat emptor!
- In the USA there are standard sizes for plumbing
fixtures, building hardware, and building construction, whereas in
Europe these things are widely variable, even in a given country.
In addition, it is often challenging to flush the toilets in the
various European countries! There are distinct commercial
advantages to living in large nations with strong central governments,
which spread across the entire continent, as in the USA.
24 January 2006: Marva Anyanwu (Wendell Green Elementary
School)
Measure your metric knowledge and What is your nano IQ?
Marva handed out a crossword puzzle relating to the metric
system, along
with some clues and the solution. In addition, she distributed
the quiz
What's Your Nano IQ?, which appears on the National Institute
of Standards
and Technology (NIST) web site:
http://www.nist.gov/public_affairs/nanotechquiz.htm.
You can take the quiz and determine your Nano-IQ, with the
following scale:
| Number Correct |
Rating |
| 0 - 3 |
Nano Novice |
| 4 - 6 |
Nano Nerd |
| 7 - 10 |
Nano Genius |
These are two very interesting nano-assignments for us and our
students. Thanks,
Marva.