This whole -3^2 thing has brought out a lot of calculator issues that the prof (and apparently the geometry and beginning algebra profs) isn't addressing. (note: It's not that calculators are required for maths, but they are prevalent, recommended, and "supported" in textbooks.)

I'm not the *only* over 30 in the class, but I am the only one who is being made to retake the class due to length of time out of school instead of coming directly from beginning algebra. I've also got a decade and a half in computer fields and some hobbysit handheld/calc hacking in my book. All of which is simply to say that I got a lot of questions today and have been pushed into the role of calc dude.

Today- I brought my 70's era ti-30 (red led), a friend's modern ti30 variant, an hp48s, 28s, 19bii, and my recently acquired hp20s. Also in class were several other ti30 variants, a ti82 and a ti83+s.

I did go buy a casio fx-115ms because of this (any excuse to blow $15 on a calculator, eh?).

Most people in the class, after spending half of it arguing about precedence, how to simplify equations for calculator input, the usefulness of parens- well, most people seemed to get it. Many of the members of the class are pissed at TI, though. Turns out the casio is an *extremely* approachable calculator with a good equation entering system and a decent solver. Not much memory space, but that's to be expected. It seems to be much more useful than anything else available for that price.

The hp20s gets similarly high marks, but it *might* be out of production and is hard to find anyway.

The RPN calcs were a bit of a difficult concept to explain, but once I got the stack explained adequately, the problem calculation of the day (what people were having trouble with) suddenly became very fun to solve and play with.

(3800ft / pi * 1.3miles)

(with the ti30 calcs, you seem to have to sto the result of

pi * 1.3 * 5280 (converting to feet)

and then recall after entering

3800 / (except that on half the ti's you can't recall in any sane method anyone in class could figure)

RPN I won't even mention, it's a waste of space considering the audience here :)

The casio was: 3800 / (pi * (1.3 * 5280) ) <enter>

Which is remarkably easy. (I added the extrea parens to illustrate the technique if you had other or more complex conversion operations in a similar EQ- such as C to F)

Makes me wonder why TI has such dominance in the market, when dollar for dollar, the casio is much better on the lower end, and the hp has so much more potential if carly will get a sanity pill.

And considering just how basic the casio really is, I'm shocked even more that HP hasn't got a good calc with similar functionality updated, modernized, and available for <$30

-Christof