John,
You can make a fine technical point to support your view and, were we at
a convention of metrologists, I would expect such precision in your
speech. However, we are addressing the issue of teaching the SI to
children for what we hope will be used by them in their quotidian lives.
Notice ...
NIST SP 811 (2008), Table B.9, p. 59, one of many examples therein:
[in three columns]
To convert from To Multiply by
watt second (W ยท s) joule (J) 1.0 E+00
What word would you propose in lieu of "convert"?
I'm coming at this discussion from a practical view, John. Not one of
technical language purity. Let's teach 'em the metric system and get
them to use it. Those who wish to become metrologists can then
matriculate to courses of study where greater care is taken with the
terminology. Second grade is too early for that.
Jim
John Frewen-Lord wrote:
Jim:
I beg to differ!
I used the word 'fundamental' in my previous email very deliberately.
With customary units, miles, yards, feet, inches (length); pounds,
ounces (mass), etc, are each discrete units, with a conversion factor to
convert one from the other (12 inches in a foot, etc, etc). As we all
know, SI does not work like that - you simply add a, or change an
existing, prefix to better reflect the magnitude of a particular
quantity. Rescaling -yes. Converting - no.
Without teaching that, you cannot understand what SI is truly about. I
got the impression in reading the Common Core State Standards that the
person who wrote those standards missed this fundamental concept
altogether - i.e. he/she wrote the metric part in the same context (i.e.
with conversion factors) as for the customary part. And to me that's
wrong.
Hence my comment - to me this is fundamental, and not simply a minor
nit-pick.
John F-L
----- Original Message ----- From: "James R. Frysinger"
<[email protected]>
To: "U.S. Metric Association" <[email protected]>
Sent: Thursday, March 11, 2010 8:05 PM
Subject: [USMA:46911] Re: Common Core State Standards for Mathematics
I suppose one could make a point for using something like "rescale" as
opposed to "convert" when changing a value statement in centimeters to
one in millimeters, for example.
However, I don't see this as a major point. The word "convert" can
mean a wide variety of things. I would say "convert common fractions
to decimal fractions" even though 1/2 is the same value as 0.5.
To me, the major focus ought to be getting the children not only to
learn metric units but also to use them! And the latter ought to
include projects and work in lessons for English, foreign languages,
art, social studies, etc.
I have a fear that if we get to nit-picky about some of these little
things, we will only make the metric system seem obscure and difficult.
Jim
John Frewen-Lord wrote:
One doesn't of course 'convert' between centimeters and meters - they
are essentially one and the same thing. This reveals a fundamental
failure to understand what the metric system (let alone SI) is about.
As for mentioning the centimeter, and not the millimeter - Pat N
should be having fits by now! Still, all part of the failure in
teaching SI.
John F-L
----- Original Message ----- From: <[email protected]>
To: "U.S. Metric Association" <[email protected]>
Sent: Thursday, March 11, 2010 7:31 PM
Subject: [USMA:46909] Common Core State Standards for Mathematics
On Page 16 of the DRAFT (for Grade 2), under "Length Measurement" is
the statement: "Understand that 1 inch, 1 foot, 1 centimeter, and 1
meter are conventionally defined lengths used as standard units.
"There is no mention of SI.
On Page 20 (for Grade 3) is the statement: "Determine and compare
areas by counting square units. Use cm^2, m^2, in^2, ft^2, and
improvised units." There is no mention of SI.
On Page 24 (for Grade 4) is the statement: "...show distances along
a race course to tents of a mile on a number line, by dividing the
unit of length into 10 equal parts to get parts of length 1/10...."
There is no mention of SI.
On Page 28 (for Grade 5)is the statement: Convert among differently
sized standard measurement units within a given measurement system
(e.g. feet to yards, centimeters to meters, and use conversions in
solving multiple word problems." also "...determine and compare
volumes...by counting cubic units (using cm^3, m^3, in^3,ft^3, and
improvised units." There is no mention of SI.
These are all the measurement related statements I have found to
data. The failure to even mention SI is a serious omission in my
opinion. I expect to more formally call attention to this major
deficiency.
Gene Mechtly
--
James R. Frysinger
632 Stony Point Mountain Road
Doyle, TN 38559-3030
(C) 931.212.0267
(H) 931.657.3107
(F) 931.657.3108
--
James R. Frysinger
632 Stony Point Mountain Road
Doyle, TN 38559-3030
(C) 931.212.0267
(H) 931.657.3107
(F) 931.657.3108
