I remember seeing my sister's maths books in the 1970's where they were trying to introduce different bases to 14 and 15 year-olds. (She is 10 years my junior). The books were an unmitigated mess and probably served to confuse rather than to educate the children.
_____ From: [email protected] [mailto:[email protected]] On Behalf Of Paul Trusten Sent: 24 April 2010 21:16 To: U.S. Metric Association Subject: [USMA:47265] Re: mastery of the SI prefix logic (was Re: Re: Metrication in Africa) I recall my 8th-grade math teacher (1964) calling what he taught "modern math." Duh. Looked like plain ole' algebra to me. ----- Original Message ----- From: [email protected] To: U.S. Metric <mailto:[email protected]> Association Sent: 24 April, 2010 14:43 Subject: [USMA:47263] Re: mastery of the SI prefix logic (was Re: Re: Metrication in Africa) Maybe restricting prefixes in daily or industry-specific SI usage is simply a dodge to circumvent underlying innumeracy. Back in the sixties we tried to teach New Math here in the States, which included teaching numeration systems using bases other than ten. It did not go well and perhaps it was tried with children who were too young. Nonetheless, at sufficient maturity most children in math classes should be able to denote cardinal numbers in any reasonably small base with relative ease; if they do not, they have still not yet fully grasped the concept of positional numeration systems using a fixed base. We certainly expect software and computer engineers to do so when it comes to base two and sixteen! -- Ezra ----- Original Message ----- From: "Paul Trusten" <[email protected]> To: "U.S. Metric Association" <[email protected]> Sent: Saturday, April 24, 2010 12:17:03 PM GMT -08:00 US/Canada Pacific Subject: [USMA:47262] mastery of the SI prefix logic (was Re: Re: Metrication in Africa) I think Gene is approaching the point I would like to make about SI. The value of the SI goes beyond the mere freedom to select a particular scale of unit. It is that metric education must have, as its goal, mastery of the prefix logic. Students should be able to move a decimal point mentally, and be able to tie their choice mentally their choice of scale. I bristle when I hear people saying that "we should use the [decimal fraction or multiple]base unit. To me, this has always sounded like choosing inches, here, feet there. It is divisive. It is a throwback to the way we thought in traditional units. The beauty of the SI is that it is logically unified. I would want metric education to give people facility in choosing a prefix. For example, $0.25 is always read "twenty-five cents" even though it is written in fractions of a dollar. If something is written as centimeters, the user ought to have been trained to "see" the millimeters and the meters as well. On my New Zealand tape measure, the marks run from 0 mm to 8 000 mm, but that does not mean the user is "prohibited" from reading 1.23 m or 12.3 cm or 123 mm. Of course, the correct SI symbol should be used, but otherwise, there should be no dilution of the concept. No one should EVER have to memorize,"OK, 1 000 m = 1 km, 1000 g = 1 kg..." The SI prefixes are a road map to the powers of 10. Paul T. ----- Original Message ----- From: <[email protected]> To: "U.S. Metric Association" <[email protected]> Sent: 24 April, 2010 13:26 Subject: [USMA:47261] Re: Metrication in Africa > > Pat, > > Here are some comments on your analysis of the blog: > > The choice is "What is the optimum SI *Prefix* to use for a particular > application?" not "What is the choice of SI Unit for that particular > application?" > > If one accepts that SI is superior to any other "collection of > miscellaneous units," the "complete set of coherent SI Units" is already > fully prescribed. Only the SI prefixes remain to be selected for various > applications. > > We are all aware that you recommend the prefix "milli" rather than the > prefix "centi" for all applications to the unit "meter" BUT the SI unit is > "meter" in both cases. > > Others, including myself, recommend the freedom to select the prefix centi > as in "centimeter" for human clothing measurements and other applications > that do not require the convenience offered by the prefixes milli, micro, > nano, etc. > > Gene. > > > ---- Original message ---- >>Date: Sat, 24 Apr 2010 20:23:22 +1000 >>From: Pat Naughtin <[email protected]> >>Subject: [USMA:47256] Metrication in Africa >>To: "U.S. Metric Association" <[email protected]> >>Cc: USMA Metric Association <[email protected]> >> >> Dear All, >> I just found this >> page >> http://course-civil-engineering.blogspot.com/2010/04/how-metric-system-was-i ntroduced-in.html >>... > Pat's comments (not necessarily Pat's recommendations): > ...choose just one single unit if you >> can. >> For example, >> All drinks will be measured in millilitres. >> All buildings will be measured in millimetres. >>... >> In the teaching institutions, on the other hand, the >> rules were (and still are ?): >> 1 Choose as many units as you possibly can. >>... > 2 Encourage conversion between all the metric >> system units that you have chosen. Don't forget to >> include all the ones you have made up. > > >
