[Edu-sig] number-line graphics for teaching arithmetic

[Kirby Urner]

>> As mentioned at my "Getting Inventive with Vectors" at 
>> http://www.inetarena.com/~pdx4d/numeracy1.html ,
>
>... I think that URL should be
><http://www.inetarena.com/~pdx4d/ocn/numeracy1.html> ...

Thanks -- a mistake I make more often than I care to admit.

>I followed your references about Grassmann and I'm interested in
>learning more.  Can you refer me to some good books on the subject?
>I took many Math classes in college (too many years ago) so I can
>handle an in-depth presentation.  I've meant to learn differential
>geometry for many years, ever since picking up Wheeler's "Gravitation"
>book, but have never taken the time to do so.  Maybe this study will
>edge me into it.  While browsing in the bookstore I encountered a book
>called "Geometric Transformations" by Mortenson.  Is that a good
>reference for this subject?
>

I think the best reference, or a very good one, is 
Michael J. Crowe's 'A History of Vector Analysis:  The Evolution 
of the Idea of a Vectorial System' (Dover, 1967, 1994).  And 
because it's Dover, it's highly affordable (unlike Springer-Verlag 
stuff, which tends to be pricey).

Kirby