Saturday, 6 August 2011

"You'll like this, it has buttons" #2

click to enlarge
David Mamet's play Edmond has as its central premise the aphorism that "Every fear hides a wish". Maybe this was behind my initial distaste of the pink Casio FX-83GT Plus, as I just decided to embrace my pink side and get one.

I confess to being a slight calculator geek, but beyond the curiosity value, this turns out to be an extremely nice calculator. As you see, it's lightweight and slimline, the battery augmented by a solar panel, and comes with a robust slip-on cover. It also features an interestingly different but highly intuitive logic.  I'm most used to the "immediate execution" style of calculator:

input ... display
7 ... 7
x ... 7
6 ... 6
x ... 42
5 ... 5
x ... 210
4 ... 4
= ... 840

The FX-83GT Plus, however, uses what Casio calls "Natural-V.P.A.M."(Visually Perfect Algebraic Method) which shows you the expression as you build it, and only returns the result when you press =.

input ... display
7 ... 7
x ... 7x
6 ... 7x6
x ... 7x6x
5 ... 7x6x5
x ... 7x6x5x
4 ... 7x6x5x4
= ... 7x6x5x4 ... 840

( ... (
7 ... (7
+ ... (7+
6 ... (7+6
) ... (7+6)
x ... (7+6)x
( ... (7+6)x(
5 ... (7+6)x(5
+ ... (7+6)x(5+
4 ... (7+6)x(5+4
) ... (7+6)x(5+4)
= ... (7+6)x(5+4) ... 117

I'm probably way behind the times in not having encountered this style of calculator logic before, but I like it a lot.

The FX-83GT Plus - see the Casio page - is aimed at the educational market and permitted for use in all UK and Irish school exams, and while it's not a graphing calculator, it does all you'd want as a basic scientific calculator for pure and applied maths up to O Level. It covers all the usual trig and transcendental functions plus stats, with a few nice bonus features such as prime factorization, exact storage of fractions and recurring decimals, assignable variables, polar/rectangular coordinate conversion, table generation from a function, and a verify mode for testing equalities or inequalities.

It has mathematical limitations - it won't do calculus, complex numbers or equation solving (for that you'd need the FX991ES Plus) - but altogether it's extremely good value. For my desktop use, anything everyday where I wouldn't use a PC maths package, I've now promoted it to be my regular calculator.

- Ray


  1. Yet more brownie points for "embracing your pink side" to this extent.

    Something I haven't yet done myself, but you have prompted me to a decision that I will do so.

    I keep a set of twelve of this calculator (or its functionally almost identical predecessor, because there are always students* who have forgotten or lost or broken their own. I have never included pink ones because I didn't want to pander to gender sterotypical assumptions amongst those students ... the pink ones weren't available when I started assembling this set, or it would (I am only now thinking) have been nice to get ALL pink! :-)

    Since I, too, use it as my personal desk calculator, however, you have inspired me to get two pink ones for my own use ... one for the desk, and one for my own use as a principled demonstration alongside the set of twelve.

    Thanks for the consciousness raising :-)


    *(In practice, it's fine at a pinch up to A-level; for the maths in a degree that isn't maths, physics or engineering; and in fact much better than nothing most of the time even for degrees in those subjects)

  2. Is math(s) still taught "long hand?" If not, has that led to a change in ability to calculate? Do students see things different if they do even simple addition on a calculator?
    Inquiring minds would like to know.

  3. I'm sure Felix can answer that better than I can.

    But some data points that may be relevant (I discussed this Felix a while back): I sometimes answer maths questions on Yahoo! Answers, and notice repeated problems that suggest some areas aren't well taught.

    One is difficulty with "word problems" - expressing verbally stated problems in mathematical form (for instance, "An apple and two oranges cost 80p. Two apples and three oranges cost £1.35" -> a + 2b = 80, 2a + 3b = 135).

    Another is the number of questions requiring heroic application of the BODMAS order of operations. It seems that in US schools at least, students aren't being taught what I'd view as good practice: explicit bracketing and spacing to make expression structures completely unambiguous.

    Still, I'm not going to go all reactionary about this. Maths teaching when I was at primary school wasn't so great. It was all "trick and tick" - teaching the manipulations necessary to get the result (things like "cross-multiplication") without teaching any understanding of the meaning.

  4. Thanks, Ray. I was in that lucky generation that had Sputnik goosing on the proletariat to bigger and better things. I liked/love math(s) and my path was strewn with roses. Now, children seem to hate it because it doesn't lead to a job that will get them jazillions of $$ (or euros or pounds) and that cute little Lamborgini. I would gladly go into a secular hermitage where people talked Fourier transforms and eigen values before dinner and Klee or Bach after. Call me an antique. (Oh, don't forget Borges, and that's not Victor, although he's not all that bad)

  5. I think that I'm of the same generation ...

  6. Very belatedly ... yes, children are taught to calculate longhand ... and, more important, perhaps, they are taught to always do an approximate mental or paper check on the order of magnitude of their calculator answer.

    However ... being taught to do it doesn't mean they actually do it unless forced to do so.

    At GCSE (for DrC: the exams taken by most young people at age 16), at least fifty percent of the marks are for work done without a calculator. One of the two equally weighted papers prohibits use of a calculator, the other one requires it. There is of course material in both papers (symbolic algebra, for example, and formal geometry) where a calculator is of no use. Then there is the requirement to show method and process for some marks, as well as the answer. Many teenagers do far less well in the nonCalc paper than in the Calc one, and lose a marks through not showing intermediate process.

    At A-level (for DrC: exams taken by about those 18 year olds who pursue post compulsory academic learning), the requirement to demonstrate nonCalc ability is abandoned.

  7. By the way ... my decision to get a pink calculator was frustrated by colour prejudice.

    The cheapest pink one I have found is three times the price of the cheapest black one. I appear to be too mean to pay that much of a differential for pink...

  8. I got mine in Sainsburys, where they had a BOGOF offer on one of each.