When I was in school 40 years ago, everybody complained about the dreaded "story problems", or the "word problems". I later came to understand that the word problems are what it was all about. Pierre gives us some very good examples of the benefits of teaching the conversion process, when done the right way. By mastering the process of converting things (units), a person is honing skills that that will serve them the rest of their lives as they face problems in everyday life.
The problem with the real world is that it is, well, real, and not ideal or theoretical. Problems come at us in all kinds of ways and if it doesn't "look" right with just the right prefix or have the "proper" symbol following it, there are those who won't be able to figure it out. I had foreign (non US) students in many of my college classes that would do very poorly on exams because the problems were not replicas of the examples given in class. While we Americans may be regarded as cowboys or renegades or nonconformists, one of the things we do fairly well is to take what we have learned in one situation and figure out how to apply it to a new situation. Doing the word problems helps to develop this type of reasoning and problems solving skills. Having a student have to figure out how to get from one unit to an equivalent unit in another system is an element that should never be removed from the educational system. And, the earlier the tools are introduced, the better they are learned. Aaron On Wed, Oct 7, 2009 at 8:26 PM, Pierre Abbat <p...@phma.optus.nu> wrote: > > On Wednesday 07 October 2009 13:55:41 John M. Steele wrote: > > How about in English and/or history classes? > > No need for English units in English classes ;) History, yes. Besides > "battles > and dates and all that rot", there are historical events such as the > division > of public lands, the Treaty of the Meter, and the destruction of Britain's > measuring standards that pertain to measurement. Anyone reading old > documents > is going to run into old units: the tax mentioned on the Rosetta Stone is > measured in ardebs per arura, for instance. > > > Conversions are the work of the Devil, especially as they are taught > here. > > The conversions between Customary and metric seem to be chosen to make > > students dislike the metric system. I would prefer math time to be spent > > teaching them to measure and use metric properly. > > History is the proper place for archaic units, and a lot of > interconversion > > needn't be taught at all; the point is to get people to quit using them. > > There is a proper way to teach conversions, namely by using the definitions > of > units. When the pupil is learning algebra, he can be given problems > involving > the gallon, which is defined in terms of the cubic inch, with the inch > defined in terms of the meter, and then figure how many microliters are in > a > gallon. Or given the definitions of various temperature scales, he can > figure > out what temperature, in degrees Celsius, is the same in rankines as > degrees > Réaumur. What should *not* be done is give a rounded conversion factor for > gallons to liters, or pounds per square inch to pascals, or whatever; or > have > measuring devices calibrated in Customary or inch-pound units. > > Some more interesting problems can be made from standards such as ISO paper > sizes or Renard numbers. For paper sizes, one could figure out which size > is > closest, proportionately, to a square meter divided by a power of two and > how > close the aspect ratio is to sqrt(2). > > Pierre > >
