On May 16, 8:23=A0am, Dom <DR...@[EMAIL PROTECTED]
> wrote:
> On Apr 25, 7:36=A0am, Pubkeybreaker <pubkeybrea...@[EMAIL PROTECTED]
> wrote:
>
>
>
>
>
> > On Apr 25, 2:58=A0am, Beliavsky <beliav...@[EMAIL PROTECTED]
> wrote:
>
> > >http://www.nytimes.com/2008/04/25/science/25math.html
> > > Study Suggests Math Teachers Scrap Balls and Slices
> > > By Kenneth Chang
> > > New York Times, April 25, 2008
>
> > > 'One train leaves Station A at 6 p.m. traveling at 40 miles per hour
> > > toward Station B. A second train leaves Station B at 7 p.m.
traveling
> > > on parallel tracks at 50 m.p.h. toward Station A. The stations are
400=
> > > miles apart. When do the trains pass each other?
>
> > > Entranced, perhaps, by those infamous hypothetical trains, many
> > > educators in recent years have incor****ated more and more examples
> > > from the real world to teach abstract concepts. The idea is that
> > > making math more relevant makes it easier to learn.
>
> > > That idea may be wrong, if researchers at Ohio State University are
> > > correct. An experiment by the researchers suggests that it might be
> > > better to let the apples, oranges and locomotives stay in the real
> > > world and, in the classroom, to focus on abstract equations, in this
> > > case 40 (t + 1) =3D 400 - 50t, where t is the travel time in hours
of
> > > the second train. (The answer is below.)'
>
> > This claim is ridiculous. =A0Learning how to translate a verbal
> > statement of the problem into equations is far more im****tant
> > than the mindless manipulations used to solve (in this case)
> > linear equations. =A0The latter only involves application of an
algorith=
m.
>
> The claim is indeed ridiculous! =A0The im****tance of translating word
> problems--identifying unknowns, defining variables, deriving
> equations--is demonstrated by the following true incident that was
> published in the April 1994 issue of The Mathematics Teacher and was
> reprinted in the February 1996 issue of The American Mathematical
> Monthly (p. 146).
>
> "[...] a very young bright CPA [partner] called me into his office and
> asked how a person could possibly calculate a bonus if the company's
> formula required that the bonus be 15 percent of the net profit after
> the bonus has been deducted!
> I showed him the linear equation B =3D 0.15P/1.15. =A0He was
> flabbergasted."- Hide quoted text -
>
> - Show quoted text -
you should have shown hin the derivation.
1B =3D .15 (P-B)
1B =3D .15P - .15 B
1.15B =3D .15P
B=3D.15P/1.15 QED
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