32 of 35 people found the following review helpful
Good for school, may be not so good for general use.,
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This review is from: Casio FX-991ES Calculator (Accessory)
I've always owned Casio calculators. I've still got one which is 25 years old! Any time I've used other makes I find the layout or method of operation hard to get used to.
I'd resisted buying a new calculator for a long time as I'm one of the "oldies" who has become used to the "immediate execution" input method of the older models, but time moves on, and you can't deny that the rationale of the newer "perfect algebraic logic" models is more sensible.
This is the top non-graphic model Casio currently make. It does pretty much everything you're ever likely to want from a non-programmable, non-graphic calculator. However, I feel the ease-of-use has been compromised in various ways that makes me wonder if a more basic model would actually be better:
This model supports seven independent memories, which is nice, but sadly the normal scratch-memory found on simple models now requires two/three keypresses to access (SHIFT-STO-M or RCL-M), just the same as the other six memories. Bring back "M in" and "MR" buttons!
It can use the content of the other six memories to do simplistic algebraic equation solving. However, the input method in this mode is so cumbersome it's actually quicker to scrawl a bit of algebraic rearrangement on a scrap of paper and work it out yourself.
The same applies to many of the other "helpful" modes, although one could argue the Matrix mode is useful to avoid user error with the long-hand method, although it will only support 3x3 matrices maximum.
There are a large number of useful physical constants and conversion factors built-in, but they have missed a trick by not presenting them by name, instead requiring you to enter them by number (there's a crib-sheet on the inside of the sliding case), *after* which it will tell you the name of (but not the value of) your chosen factor!
The distinguishing marketing feature of this model is supposedly its ability to display the maths you're inputting in a more natural form. Sadly it doesn't really even manage to do that properly, as you have to press special keys to get one-over-the-other division layout, and a far too frequent use of the cursor keys to jump about within that layout. Yet it doesn't in reality gain you anything if you know the slightest thing about algebra in the first place, as you'd simply use the standard divide key and parenthesis.
Overall, whilst this model has a comprehensive feature-set and is quite nicely made, I can't help but feel it is aimed at students with little skill in maths in an effort to allow entry of poorly-understood textbook/exam question and provide an answer. For the more average maths-capable student or someone in full-time work who needs a slick calculation tool to do the donkey-work of some complex problem, you end up using this calculator in a manner similar to one of the lesser models (i.e. direct line-entry of the basic functions), completely ignoring any of the relatively exotic features of this larger-screen model.
Conclusion: Decent, but ultimately flawed and overly cumbersome. Not enough focus on basic usability, with some obvious missed opportunities to utilise the large screen for the best.