Re: Sophisticated calculators

["Carmen K. Shepard" <ckshep01@pop.uky.edu>]

At 03:34 PM 4/6/98 -0400, Ludwik Kowalski wrote:
 (snipped message about TI 83 calculator)
> I know it is not wise to formulate an opinion on the basis of a one-day
> impression. But I have a desire to share these reflections. What do you 
> think about graphic calculators? 

I was given a TI graphing calculator (I think it was an 82, but I'm not
sure) three years ago.  I never used it for anything besides the 
standard calculator stuff, and I found it impossible to remember how
to change the darkness of the screen.  Many of my students had this
calculator or a very similar one, and few of them had any idea how to
use it.

Two years ago I was given a TI 92 calculator and a week-long workshop
to learn how to use it.  This calculator I use all the time.  It has 
a QWERTY keyboard and you can select commands from menus or you can
type them in.  I type them, my students almost uniformly select them
from a menu.  The solve and simult commands are nice for working problems.
I have a view screen for an overhead projector that I use when we talk
about waves.  This way my students don't have to suffer through my 
drawings of waves.  The screen is relatively large, although you can
easily find graphs that don't look right because of the pixels, and if 
you have a lot of simultaneous equations to solve, your answers won't fit
on the screen without being tricky about it.

I haven't managed to get Tetris to run on it yet, though.  I guess that
will be my project for this summer. :)  

We loan TI 92s out to students enrolled in trig, calculus, and physics.
We also loan out the manual, but very few students borrow it and I doubt
if any look at it.  (To be fair, it is 500+ pages long.)  I had hoped
that the students who could not do the algebra by hand would use the
calculator to do it for them.  Mostly they claimed that it was too 
difficult to do on the calculator, and they solved their equations 
by guessing at random, apparently.  The students who understood the 
math already and could solve simple algebraic equations by hand were
very quick to use the calculator instead.

> How many of you use them in the CBL 
> activities? I also was motivated by the prospect of taking students 
> outside for data gathering. But I may change my mind. The learning curve 
> is so steep. And climbing it is so unpleasant. The MBL activities are much 
> more attractive in that respect. 

I don't use CBL activities, but some of the math teachers here do.
I have one CBL and ten computer lab interfaces, so we use the computers.

> Yes, sophisticated calculators are less 
> expensive than computers. But are they worth using? What evidence is 
> available that teaching high school mathematics with them is more 
> productive than teaching it traditionally? 


This is what I'd like to know, too.  What works best with calculators,
and what should we stay away from?  How much instruction on using the
calculators do we need to give so that the students can use them 
productively?  (We just got a notice that we are supposed to use new
technologies in our classes, but we aren't supposed to teach our 
students how to use them.  I haven't figured that one out yet.)

Carmen Shepard