My name is Martin Cohen. I work as a
computer programmer. My college education was in mathematics and
I have had a lifelong interest in both mathematics and the
teaching of it. On this page I present several topics in high
school level mathematics.

We are constantly being told about how
poorly Americans are doing in science and mathematics. I don't
know how much truth there is in all this. I do know that we are
living in an age of information and that our schools have not yet
adjusted. The ability to reason abstractly is going to be of
increasing importance.

When I went to college I did some
substitute teaching between the end of the college year and the
beginning of the public school summer vacation. Nobody expected
me to teach anything so to give the students something to do I
presented several problems in recreational mathematics. We all
know the type of respect that substitute teachers command. I was
therefore quite pleasantly surprised by both the enthusiasm with
which the problems were tackled and by the ability of the
students to solve them. This was the case for both advanced and
less advanced classes. Some of the problems I presented were
fairly challenging.

It is clear to that nearly everyone has
an intrinsic interest in mathematics; it is simply a matter of
being able to tap into it. Everyone should come out of high
school being able to perform basic algebra. In the examples I am
assuming knowledge of algebra. The topics covered are normally
either not presented in high school or are not thoroughly
covered. These are all ideas that I either came up with on my own
or read about after leaving public school. The topics proceed
from concrete examples to abstract principles. I welcome any
comments on what I present. I also welcome any ideas on how to
teach mathematics in public school. If you provide the latter,
please try to be as specific as possible. It amazes me how people
can talk endlessly about how to teach mathematics without
presenting any actual mathematics. For my part, I have dispensed
with any formal discussion of teaching principles. In this regard
I will let the examples speak for themselves.

Please give me your opinion!
Constructive criticism is welcome. In particular, I would like to know if there is anything you had difficulty following. Your feedback would be helpful in guiding me to make improvements.