On 2011/02/09, at 07:05 , Martin Vlietstra wrote:
By geometric instruments, I mean using a ruler to draw a line that is
say 85
mm long, drawing a circle using a compass, measuring angles using a
protractor. UI seem to recall having started doing this at the age of
about
10.
Dear Martin and All,
I have always thought that the teaching of measurement using millimetres
should be introduced at about the time that children change from
printing to joined-up-writing, which I thinks happens about fourth
grade. Many children see the writing change as a major transition step
in their development from being a child to being a "grown-up". I agree
with Jim Frysinger that small children might use centimetre markings as
a form of counting stick, but I think that measuring in millimetres is
appropriate when it is time for real "grown-up" measuring. Keep in mind
that our experience in Australia that the vast majority of work in
Australia is done using millimetres only.
It seems to me that there is a very high probability that your students
in the USA will use millimetres predominantly during their future
working lives and that this will become more and more open and honest
within your society. The energy needed to continue to hide the metric
system is becoming too great, especially in the light of the priorities
given in President Obama's State of the Union speech so many of which
will rely on the (unspoken) metric system.
The use of millimetres, I think, is one of the reasons why metrication
was so successful in Australia and done so quickly.
I’ve made an analysis of the various occupations in Australia, and the
length units they prefer to use. From the 117 occupations listed by the
Australian Bureau of Statistics, the results are as follows:
*millimetre users - 97 occupations - 83 %*
Aircraft maintenance engineer (avionics), aircraft maintenance engineer
(mechanical), aircraft maintenance engineer (structures), automotive
electrician, binder and finisher, blacksmith, boat builder and repairer,
bricklayer, broadcast transmitter operator, business machine mechanic,
cabinetmaker, cable jointer, carpenter, carpenter and joiner,
communications linesperson, computing support technician, dental
technician, draftsperson, drainer, electrical engineering technician,
electrical power line tradesperson, electrician (special class),
electronic engineering technician, electronic equipment tradesperson,
electronic instrument tradesperson (special class), electroplater,
engraver, farrier, fibrous plasterer, fitter, flat glass tradesperson,
floor finisher, furniture finisher, furniture upholsterer, gasfitter,
gem cuter and polisher, general communications tradesperson, general
electrician, general electronic instrument tradesperson, general
fabrication engineering tradesperson, general gardener, general
mechanical engineering tradesperson, general plumber, glass blower,
graphic pre-press tradesperson, greenkeeper, gunsmith, jeweller, joiner,
landscape gardener, leather goods maker, lift mechanic, locksmith,
mechanical engineering technician, mechanical services and air
conditioning plumber, medical grade shoemaker, metal casting
tradesperson, metal fabricator (boilermaker), metal machinist (first
class), metal polisher, motor mechanic, optical mechanic, painter and
decorator, panel beater, patternmaker-grader (clothing), piano maker,
piano tuner, precision instrument maker and repairer, pressure welder,
printing machinist, refrigeration and air conditioning mechanic, roof
plumber, roof slater and tiler, saw maker and repairer, screen printer,
sheet metal worker (first class), shipwright, shoemaker, sign writer,
small offset printer, solid plasterer, stonemason, surveyor, textile,
clothing or footwear mechanic, toolmaker, upholsterers and bedding
tradespersons, tree surgeon, vehicle body maker, vehicle painter,
vehicle trimmer, wall and floor tiler, watch and clock maker and
repairer, welder (first class), wood tradesperson, and wood turner.
*centimetre and inch users - 12 occupations - 10 %*
Apparel cutter, baker, canvas goods maker, chef, cook, dressmaker,
general clothing tradesperson, nurseryperson, pastry cook, picture
framer, sail maker, and tailor.
*8 occupations where length measures are relatively unimportant - 6 %*
Butcher, buttermaker, cheesemaker, confectioner, ladies hairdresser,
smallgoods maker, men's hairdresser, and meat tradespersons.
You might also notice that nobody in Australia regularly uses
decimetres, decametres or hectometres at all. Except for the
non-preferred centimetre by most occupations, the prefixes centi, deci,
deca, and hecto are essentially never used in daily activities and maybe
they shouldn't be taught in any detail – simply make mention of their
existence. In the rare cases where these prefixes are used, and these
are rapidly becoming rarer, these odd prefixes can soon be learnt.
Certainly students shouldn't bother with converting to or from them.
Another point to notice is that where an industry chose to use
centimetres the metrication upgrade has been accompanied by almost
continuous debate (often extremely bitter) and it has always been
painfully slow. The users of millimetres only completed their
metrication upgrades typically in a year or two while the centimetres
users are still quibbling after 41 years (and counting). The success of
the millimetres only approach seems to me to have had rapid success
because nobody in these industries now has to use anything but whole
numbers of millimetres - there are no decimals and no vulgar or common
fractions at all. Granted there are some seemingly large numbers but, if
this frightens you and you win 20 565 dollars in a lotto next week,
please let me know and I will happily take $20 000 of it to ease your
mind back to a smaller number!
I consider that it’s best to keep it simple in schools, and to only
teach the four prefixes: micro, milli, kilo, and mega. This
recommendation is appropriate when your goal is metrication and a
relative fast way to get the personal mind-set of children focused on to
the practical use of the metric system active in their own lives.
If your goal is to teach the Système International d'Unité (SI) in all
its finery from yocto to yotta in elementary or middle schools and to
teach the slithering and sliding of decimal points all about the place,
then I suggest that you are using the metric system as a crutch to teach
an aspect of pure mathematics. I don't think it is appropriate to use
the metric system as a tool for this purpose. Generally industry does
not do this; they choose a single prefix so they can operate almost
totally in whole numbers and the let the prefix do the work. Changing
from metric system prefix to metric system prefix is sometimes done but
it is relatively rare in industry.
Cheers,
Pat Naughtin
Geelong, Australia
-----Original Message-----
From: [email protected] <mailto:[email protected]>
[mailto:[email protected]] On Behalf
Of [email protected] <mailto:[email protected]>
Sent: 08 February 2011 19:59
To: U.S. Metric Association
Subject: [USMA:49815] Re: STEM metric foundation in America Proposal
Martin, Please explain what you mean by "geometric instruments" and at
what
age (or grade) level they should be employed in education about SI.
Gene.
---- Original message ----
Date: Tue, 8 Feb 2011 19:32:21 -0000
From: "Martin Vlietstra" <[email protected]
<mailto:[email protected]>>
Subject: RE: [USMA:49798] Re: STEM metric foundation in America Proposal
To: <[email protected] <mailto:[email protected]>>, "'U.S.
Metric Association'"
<[email protected] <mailto:[email protected]>>
I suggest that millimeters should be introduced as part of teaching
the use
of geometric instruments.
-----Original Message-----
From: [email protected] <mailto:[email protected]>
[mailto:[email protected]] On Behalf
Of [email protected] <mailto:[email protected]>
Sent: 08 February 2011 02:40
To: U.S. Metric Association
Subject: [USMA:49798] Re: STEM metric foundation in America Proposal
Great idea, Tim. Use the STEM and "Competitiveness" initiatives to
promote
SI.
The "kits" must be appropriate for grade level. i.e. Different contents!
NIST standard SP 811 is *free* and should be included, at least for High
Schools.
The centimeter *is appropriate* for early elementary pupils as Jim
asserts.
The millimeter is best for industry, but not for elementary education.
You include "mass sets" with the balances. Fine! But "weight" sets
contradict a resolution by the CGPM that "weight is a force" not
identical
with mass.
Gene Mechtly.
...
Pat Naughtin LCAMS
Author of the ebook, /Metrication Leaders Guide,/ see
http://metricationmatters.com/MetricationLeadersGuideInfo.html
Hear Pat speak at: http://www.youtube.com/watch?v=_lshRAPvPZY
PO Box 305 Belmont 3216,
Geelong, Australia
Phone: 61 3 5241 2008
Metric system consultant, writer, and speaker, Pat Naughtin, has helped
thousands of people and hundreds of companies upgrade to the modern
metric system smoothly, quickly, and so economically that they now save
thousands each year when buying, processing, or selling for their
businesses. Pat provides services and resources for many different
trades, crafts, and professions for commercial, industrial and
government metrication leaders in Asia, Europe, and in the USA. Pat's
clients include the Australian Government, Google, NASA, NIST, and the
metric associations of Canada, the UK, and the USA. See
http://www.metricationmatters.com
<http://www.metricationmatters.com/>for more metrication information,
contact Pat at [email protected]
<mailto:[email protected]>or to get the free
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