Yes, clearly the area should have been given as 8000 km2. Probably the
single most common mathematical mistake that people make is failure to round
off to an appropriate precision. Often this happens in converting from
wombat to SI, but that doesn't seem to be the case here. Unfortunately, high
school math courses DO NOT teach significant digits and the rounding rules.
If students learn that at all, they learn it in science courses. In middle
school, students learn a little about rounding, but they are taught that
it's used for "estimating" or "approximating." The concepts of precision and
accuracy are not taught in math, nor is the notion that ALL measurements are
approximate. Unless they hear about it in chemistry or physics, they are
unlikely to hear about it at all. Even our best students insist on
expressing too many digits in their answers. You can tell them to round off
a hundred times and still they resist.
> -----Original Message-----
> From: Duncan Bath
> >
> Globe & Mail [A3], Mar 08:
> "What's killing Mexico's Monarchs: .."
>
> In this article, by a "science reporter", reference is made to ".. a
> 795,000-hectare model ..". This raises two questions re the rational use
> of numbers:
>
> a) with areas this large, why not refer to 7,950 square kilometres -
> this is easily envisaged by all but the most profoundly numerically
> challenged as (say) about 80 km by 100 km
>
> b) using high-school math teachings concerning 'significant
> digits', why
> not refer to 8,000 square kilometres. This "rounding" process involves a
> discrepancy of well less than 1% and should be entirely appropriate in
> this context.
>
> Duncan
> DT Bath, 861 Kensington Dr., Peterborough ON K9J 6J8
> (705)743-4297
>
>
