While I cannot say that I speak for 100% of Americans, I think I can safely state that when most people in the USA refer to a "yard", they are talking about the one with 36 inches in it. And, each one of those inches is equal to 25.4 mm. We don't know what year it was approved, agreed to, standardized or redefined. What's more, we don't care. It equals thirty six 25.4mm inches.
Unfortunately, the point of my post was pretty much missed by everybody that responded. My point is, that the PROCESS of doing conversions develops skills that are related to and involved in the PROCESS of SOLVING problems. If a person can't set up the problem, then they can't solve it. If you can't set up the factors to perform a lengthy conversion, then you can't perform the conversion. The processes are very similar. Critical thinking and reasoning skills are only developed through practicing them. You can't look them up in a book or an ISO standard. If you withhold the teaching of the process of doing conversion completely, or until high school, you are withholding a tool that is an easy and fun way to start getting kids to THINK about what they are doing and why, and what they can do with a given piece of information. I didn't mean to touch a sensitive spot, but I get tired of hearing the members of this forum run down Americans as being "dumb" or "inferior" because we haven't yet adopted the SI to the degree that many out there think we should. Best regards. Aaron Harper On Thu, Oct 8, 2009 at 12:19 AM, Pat Naughtin < pat.naugh...@metricationmatters.com> wrote: > On 2009/10/08, at 14:40 , Aaron Harper wrote: > > Having a student have to figure out how to get from one unit to an > equivalent unit in another system > > > > Dear Aaron, > I am having trouble with your line, '*Having a student have to figure out > how to get from one unit to an equivalent unit in another system …*' as I > know of only one system of measurement. > > And I am also sure that only one system of measurement has ever existed. > > When the decimal metric system was developed from Wilkins *universal > measure* in the 1790s, it became the world's first measurement system. > Subsequently this first idea for a measuring system evolved from the *decimal > metric system* through the simpler name of *metric system *to the > *International > System of Units (SI)*. > > As you know this is a complete system of units that is able to measure > everything from the smallest to the largest things in the entire Universe. > As Condorcet put it in the early 1790s, the decimal metric system is: > > '*for all time; for all people*'. > > I am aware that there were subsequent refits of bits and pieces of various > small groups of old measuring words. The UK tried to develop a decimal > currency based on 10 florins to a pound in about 1824 while they held to the > idea of 24 pennies to a florin. > > Some scientists tried to copy the coherent properties of the metric system > with their foot-pound-second "system" and the foot-poundal-second "system" > while some engineers tried to do the same with their > foot-slug-second "system"; all done while the foot changed its length in, at > least, these years: 1824, 1834, 1855, 1893, and 1959. I find it impossible > to recognise these attempts as comprehensive or universal measuring > "systems". > > The point that I want to make is that it is not possible to convert from > one system to another system when there has only ever been one single system > – the metric system – that is formally known as the International System of > Units (SI). All the rest are just more or less random collections of old > pre-metric measuring words. > > Now let's consider an actual conversion problem. > > *Convert ten yards into metres.* > > This problem should not even be attempted until you answer this question: > > Which yard do you mean? Are you talking about the 1859 metric-defined > international yard, the 1893 metric-defined yard, (the statute yard or the > survey yard of the USA), the interim yard between 1834 and 1855 based on the > length of a pendulum with no real fixed length, the 1855 UK yard based on an > artefact, the 1824 UK Imperial yard (1832 in the USA) that got burned with > the UK Houses of Parliament in 1834 or one of the many earlier yards that > appeared from time to time all with slightly varying lengths (possibilities > here are three Elizabeth I feet, the Edward I ulna, or three Roman feet, > etc.)? > > If you don't ask all of these questions you infer that there are two > "systems" metric and only one other, when the facts are that there has only > ever been one system – the metric system as stated above – and all of the > other old hodge-podge of measuring words with multiple definitions that have > varied through time. > > Hhhrrrmmmph! > > P.S. Apologies for being so grumpy – you've hit a pet peeve! > > Cheers, > > Pat Naughtin > Author of the ebook, *Metrication Leaders Guide,* that you can obtain > from http://metricationmatters.com/MetricationLeadersGuideInfo.html > 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 > pat.naugh...@metricationmatters.com or to get the free '*Metrication > matters*' newsletter go to: http://www.metricationmatters.com/newsletter to > subscribe. >
