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" <j...@metricmethods.com>
To: "U.S. Metric Association" <usma@colostate.edu>
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: <mech...@illinois.edu>
To: "U.S. Metric Association" <usma@colostate.edu>
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
