Subject: Innovation

Posted by Niall Palfreyman on 12/1/2010
In Reply To:Innovation Posted by Richard Turnock on 11/30/2010

Message:

Am 01.12.2010 05:52, schrieb leusa tds.net:
> How do you get a teacher interested in SD when they have a Honors
> Algebra 2 class that does not know how to simplify a radical, but they
> know how to punch the numbers in a calculator? In fact, that is
> becoming a huge problem, the kids use the calculator and really do not
> understand what they are doing, garbage-in, garbage-out. I am a firm
> believer of technology, but wisdom takes place when we balance
> technology with understanding basic mathematical rules etc.. I do not have the answer.
I also do not have the answer. However something interesting happened this year with my students which may point in the direction of a solution. Every week I hold a problem class on maths and physics exercises for my first year college students, and particularly when solving physics problems we often end up with a huge expression full of numbers which needs calculating. I'm congenitally lazy, and so refuse to use a calculator, instead working out an estimated solution in my head which I then used to check the calculator answers of my students.

After a while a student told me in class that he was amazed that I could consistently get answers which weren't much worse than those of a calculator, and the whole class asked me to show them how I estimate numbers in my head. What became apparent in the ensuing conversation (and what was new to me) was that much of what I do relies heavily on making use of little algebraic tricks like factorisation, cancelling and so forth. Could it be that this might pave the way to a discussion of algebra?

Niall Palfreyman