Both Pierre and Robert make good points. My own view is that conversion from imperial/customary units of measure to metric should be an "add-on" to a conventional teaching that is in metric. This will enable students to use old documents, but will also show them how cumbersome imperial/customary units of measure are.
This must however be backed up with society as a whole adopting the metric system, otherwise you will end up with the situation that we have in the United Kingdom - the professionals use metric while the man-in-the-street uses imperial, or to be more accurate, the man in the street quotes imperial units, but does not know how to use them (ie cannot calculate averages etc). This I believe is one of the contributory causes to the decline in numeracy that we are witnessing in the United Kingdom (and also, I understand in the United States). -----Original Message----- From: [email protected] [mailto:[email protected]] On Behalf Of Pierre Abbat Sent: 29 November 2009 14:49 To: U.S. Metric Association Subject: [USMA:46210] Re: content inch pound meter gram On Saturday 28 November 2009 14:15:05 Bill Hooper wrote: > On Nov 28 , at 1:49 PM, Robert H. Bushnell wrote: > > Conversion from inch-pound units to metric > > units may be used as examples in algebra. > > There is no good reason to teach conversion from inch-lb to metric. I disagree. If all new surveys are labeled in meters, surveyors will be working with old maps and deeds labeled in feet and chains for at least another hundred years. Not everyone will need to convert, but there are enough specialties where it is needed that it should be taught. Students should not be taught conversion of pounds, until they have demonstrated that they can multiply two eight-digit numbers by hand accurately. If they can multiply two three- or four-digit numbers, they may be introduced to feet and inches. To be introduced to the survey foot, they must be able to do long division by hand with an arbitrary four-digit denominator. Conversion shall be done with the definitions of units. When converting pounds-force to newtons, for instance, the approximate factor 4.448 must not be used. One must use the exact definition of the pound and the standard acceleration of gravity. Pierre -- lo ponse be lo mruli po'o cu ga'ezga roda lo ka dinko
