15.1.2017

Lean, mean and not messing around; beware the new kid on the block! It annihilates the FX7400GII in terms of overall usefulness, yet can be had for two-thirds of the price (though this is beginning to creep up!). Appearance wise, Casio have broken with their traditional fx-83GT/fx-991ES shape and created something very different, with a clean, new look, that's almost a work of art. Its appearance is so good, I suspect it will sell just on those grounds alone! Put simply, it has real style; you almost feel in possession of a fashion accessory! Most photos don't do justice; hopefully my photo will!Although it isn't a graphical calculator as such, it has the capacity to draw graphs on your smart phone or tablet,via a scannable QP code and an app.They've improved the statistical functions so that in addition to the standardized, normal cumulative probaility distribution, you now also get the inverse cumulative normal distribution function, plus binomial and Poisson, probability and cumulative probability distributions. These are very useful to anyone doing S1 or S2 statistics modules for A-Level, and dispense with the need for tables of these functions. Most of this is absent on FX7400GII! What it offers, however, is still way short of the fx-9750GII, in this respect.You also get the ability to solve quadratic, cubic or quartic polynomial inequalities and the answer is given just as it should be written down, using the correct inequality symbols! Even the FX9860GII doesn't offer this at present!Other enhancements include better vector facilities: it now offers the ability to show you the angle between two vectors rather than leaving you to work it out via the dot-product. The FX7400GII has no vector facilities at all and doesn't even have a matrix mode! The FX9750GII does matrices but no vector mode! Only the next one up from that, the FX9860GII, does both, apart from the FX991ES, now available at roughly £16.For some, the cherry on the cake will be the addition of a basic spreadsheet mode (absent on the FX7400GII and the FX9750GII calculators). You also get an equation solving mode which is an enhanced version of the FX991ES. It now features a 'Solv' facility, designed to give approximate solutions, to many types of equation, as presented, using Newton's method. In this respect, however, the FX9750GII and FX9860GII are light years ahead with the 'SolveN' facility, as this often gives exact solutions (even as multiples of pi, where relevant on the fx-9860GII).You get a crystal clear, 'natural' display, with answers presented as surds, or multiples of pi, including fractions, where possible. FX7400GII can't do this and the FX9750GII only does it when uprated.The processor also seems faster than before.If there is a drawback, it has to be the fact that display history is cleared when the calculator is switched off and once you've performed a calculation, you can not go back, edit the history and recalculate, once the display shows ANS.Amazingly enough, evidence suggests that UK exam boards will allow it, despite no CAS features allowed. However mild, this calculator does have CAS features because it uses symbolic logic to write inequality regions. Fortunately, many teachers have taken to it and I suspect wires were be pulled by the more influential ones ('old boy' networks etc!) to get it approved for UK, GCE exams. Whether or not they'll achieve this for IB use, is another matter! Without an Exam Mode, similar to the FX9860GII or Graph 75/95, it would definitely be banned in France, for IB use, on account of the vector commands.It goes without saying, that now it's regarded as suitable for UK, GCE exam use, the FX991ES may now bite the dust or be offered at a lower price. This is something Casio could easily do because the circuit board is almost identical to the FX85GT-Plus, often available for under £10 and popular with GCSE students. In the past, however, Casio went to great lengths to prevent people getting too much of a bargain! Take the FX83ES as an example. It shared the same type of circuit board as the FX991ES and an HB pencil applied to the P4 jumper on it, would effectively turn it into one, from something no better than the current FX85GT Plus, within seconds. Yes!, you unleashed 5 extra modes and all the functions of FX991ES. Casio reacted by encapsulating the P4 jumper, to make it virtually impossible to do this any more.So, interesting times ahead and one does hope that models known and loved by students, here and abroad, like the FX9750GII will be around a bit longer. Ten years, however, is a long time in terms of technology and the FX9750GII first appeared in 2008! Does the FX991EX usher in the era of a new line up of scientific calculators? One wonders!In summary, there's a lot to like about Casio's new offering and one could say that at under £20, it redefines the market in the value-for-money stakes, providing many features hitherto not offered.On looks alone, it scores 10 out of 10. Its new keyboard layout, with extra keys such as OPTN (pity they didn't give it the EXIT key as well!) and main menu with attractive looking icons is also highly functional. It's slim, solar powered and has useful features not found on models costing three times the price. Here, I'm thinking of the polynomial inequality solver and the ratio solver. These will be an immediate hit with GCSE and A-Level students. Together with a basic spreadsheet facility in addition to other useful features which have been around for some time (eg matrices, vectors) and you really have an incredibly useful little machine! Some universities ban programmable calculators, so it's bound to have great appeal there!On the downside, don't expect the build quality of an fx-9860GII or even an fx-9750GII and do bear in mind that both these trounce it in terms of overall usefulness to the average A-Level student. Providing the fx-9750GII's OS is upgraded to the fx-9860GII, the extra facilities could be worth at least one extra grade in the exam! Savvy students good at IT would probably jump two grades! There are certain well-known, independent, private schools, which choose these models, for their students and in the US, a yellow school edition version of the fx-9750GII, is quite common.There may be school or college teachers out there thinking they should bulk buy the new fx991-ex. I'd urge caution! £50 will be affordable to most, and just on the basis of the 'SolveN' facility alone, justifies the extra cost of the fx-9750GII. With vastly superior statistical functions, bigger screen and the ability to graph functions, it really does win hands down.Both the fx-9750GII and the fx-9860GII are fully programmable, in a language almost identical to BASIC, with the full range of commands you'd expect. This could be a real aid in getting students interested in programming. With almost every mathematical and text symbol available, you can in effect write your own software to cover anything you consider important, but absent (within reason!).So, to maximize overall grades achieved, the fx-9750GII or fx-9860GII are still 'top dog' and this new offering must be seen as very much inferior.Let me end on another negative point! Whilst the price of the fx-9750GII has come down from £65 to £49.99, in the last couple of months, the price of this one has risen (to as much as £32.50, here on Amazon). At under £20, it's stellar value for anyone wanting to cut costs. At £27, however, it's starting to look expensive. Anything more than £30, and it falls into the 'betwixt and between' category. The average GCE student should pay the extra £18 and go for the fx-9750GII. The cheapskate, however, would be better off with the fx-991ES Plus, readily available at £18 (currently about £16 on Amazon) and still a great little calculator or the Canon F-789SGA (better made than the fx991es, with slightly more functions and selling for roughly £18).WHAT SEEMS RIDICULOUS IS THAT FROM AMAZON.COM, THE UK PURCHASER CAN GET IT FOR £18.50! IN OTHER WORDS YET AGAIN, THE UK CONSUMER GETS RIPPED OFF! DON'T HAVE IT!!Let's also be quite clear that despite its good looks and superb blend of features, the fx-991EX is really just a tweaked version of its predecessor. It's not programmable, isn't a true graphical calculator, can't connect to your PC and can't take additional apps, like an fx-9860GII or uprated fx-9750GII. In short: a great little calculator but most GCE students would be far better off paying the extra for the fx-9750GII.

5.8.2019

Very occasionally, a product appears which redefines the market in its area - typically for reasons such as providing a unique blend of features, quality of construction, or price. The fx991EX has achieved this .Casio got everything right; even the appearance (more eye catching than ever before) and provided features you just wouldn't expect at the price, building on the now defunct, but excellent value-for-money, fx991ES Plus. Together with its fresh, new, attractive appearance, sporting an icon-driven menu, Casio have almost shot themselves in the foot with regards to sales of other models in their range, such as their fx7400GII, which lacks very important facilities that this one offers,yet costs a good deal more!What's all the fuss about? Let me elucidate further. To appreciate what you're getting, we need to briefly discuss the forerunner; the fx991ES Plus. Top of the league in terms of value-for-money, it solved simultaneous equations with up to three unknowns and also cubic polynomials. It coped with matrices up to 3x3 (finding determinants and inverses) and offered useful vector commands, including the cross-product. It could also do definite integration and give the numerical value of a derivative. It had a Solve Mode, capable of solving simple, algebraic equations, as presented. Its aim was to give approximate solutions, but in reality it often gave the exact solution to simple equations, of the type encountered at GCSE. Say I wanted to solve: (2x-3)/4 = 1-x/2. I could enter the equation as presented, press SOLVE and hey presto: the exact answer would be displayed : x=7/4 and a message L-R=0, telling you that 7/4 is the exact answer. It also offered cumulative Normal distribution commands, and various types of statistical regression. With its natural display, you got trig values displayed as surds or multiplies of pi, where appropriate. This, and other features, made it an incredibly good deal for something under £20, especially considering that it was dual powered (solar plus battery) and had a databank with virtually every physical constant you could think of, and highly compact. Prior to the fx991EX, no one would've thought it likely that Casio would improve on this deal. Why should they? The fact is that's exactly what they've done, and in no small way; they've taken a sledge hammer to it, and in doing so won the race in the value-for-money stakes by such a margin, that it almost seems unreal.The matrix mode now copes with matrices up to 4 x 4. The vector mode now also gives the angle between two vectors. The equation-solving mode now copes with simultaneous equations with up to four unknowns, and solves polynomial equations of order four (I.e. quartics). The minimum or maximum of a quadratic is now given (see group photo) and if that wasn't enough, it now solves polynomial inequalities (see group photo), specifying the range of values using the correct symbols. This is a c.a.s. feature which ought to be banned for GCE exams, by JQC regulations, but in fact the fx991EX is not only allowed, it's actually recommended by major examining boards!The fx991EX has more statistical functions. It now also has the inverse Normal distribution, and both the Binomial and Poison probability and cumulative probability distributions are present. If that's not enough, you also get a spreadsheet mode, dual function table facility, ratio solver, and data output to a QP code, ready to be scanned by your smartphone. With an app present, you could then plot graphs and do a whole manner of things.Anything else worth expanding on? Yes! As mentioned, the styling has a fresh, new, up-to-date look, better than anything offered before. The main menu, icon display, is not just highly attractive appearance-wise, but also very practical, to those visually orientated. Like its predecessor, it's also very compact - far more so than a graphical calculator. The functionality is fluid - you won't spend ages trying to figure out how to do something!In summay: a milestone completely redefining the market. For £20, nothing else comes near! In a sales environment, it answers the question : "What's the best scientific calculator I can get for under £25?" Unequivocally worth five stars, and one almost feels like saying thank you to Casio for ever daring to launch something so good at the price.Anything negative to say? Considering you even get a 3-year guarantee, absolutely not! I know some people out there have pointed out that A-Level Biology and Psychology students, would've benefited had it offered the Chi-Squared and t distributions. This may be true; pity a new Ferrari isn't £10K! To get these features (and lots more) the minimum you'll need to consider purchasing, is an fx9750GII, and then uprate its operating system to the fx9860GII, if you want a 'natural' display, capable of giving exact answers. Overall, you'll then have a much better calculator, but at over double the price. Unfortunately though, you'll loose the polynomial inequality solver (true even if you spend £120 on an fxcg50) and (if you uprate it) also the three-year guarantee. New, an fx9860GII costs about £68 (roughly three times the price). Again, well worth the extra, but much bigger and bulkier.Finally, a word of caution!Do beware of the Chinese copy, typically marketed by traders on the site with four letters, as the fx991EX Superwiz. It looks almost identical, except for some keyboard inscriptions, and is often claimed as having 552 functions (a lie, because in reality it's just a basic scientific calculator without even a natural display). Traders often copy and paste the Casio description into their advert, giving a totally false impression. Look carefully at their pictures, and you'll see nothing to illustrate any of advanced features claimed. As with cheap smartphones with false specifications, reporting it to customer services does no good, because when one account closes, another one opens!

2.5.2020

This is a great calculator in general, the upgraded fx-991ES PLUS.What I find great:- Has all the features of the fx-991ES PLUS, with a new UI that renders even more closely to Maths textbooks (Roman font)- Calculus & complex numbers (as did the fx-991ES PLUS)- Binary Octal & Hex modes with Boolean logic operators and two's complement binary arithmetic- Matrix, Vector and equation solving all a little slicker than the fx-991ES PLUS- Stats also nicely upgraded with an added spreadsheet functionality.- The ability to copy results to a smart device using QR codes (and the accompanying Casio WES mobile app) works quite well; you can even copy your results to MathML and LaTeX from the appAnd the Prime Factorisation function,

10.8.2020

Outside of a graphing calculator, which is a much more expensive and complex proposition, this has to be the best you can get. Casio has spent years refining the way these things work, and it shows. The keyboard, for instance, is faultless. The display, considering it's not backlit, is very clear, and higher resolution than in previous models so you can have more rows in a table or spreadsheet. It's a very fast calculator too, with most operations happening instantly. Mostly it works on solar power, and there's a little 'sun' icon to tell you this is happening. If the light's too dim, the LR44 backup battery will take over, and since this is just about the most widely available button cell battery,

21.3.2016

All my students love this calculator. They love the new look and they especially like the easier to use functionality.This calculator does not do much more than the 991-ES bu the smaller high resolution graphics make the calculations easier to see and understand. The new menu system is much easier to follow and although it does not do more than the previous version, it seems like it can. Most of my students using this calculator found and started using functions and equation which were easier to find and thus more usable.This makes simultaneous equations and solving quadratics a breeze. Both my A level and GCSE students have started to enjoy some of the calculator questions more.

25.4.2016

As a little bit of a calculator nerd, I've used many different calculators over the years. When it comes to scientific calculators there is a vast range to choose from, Casio being at the forefront of those avaliable and often the go to calculators for many students. However, as time progresses even with experience in using the relatively simple Casio-style scientific calculators, according the more complex functions can be a little bewildering.I heard about the FX-911EX approximately a year ago when they were first released in Japan and extremely hard to get hold of. I was amazed by their high resolution display to allows the calculator to display full text rather than abbreviations. For example,

22.5.2019

As a little bit of a calculator nerd, I've used many different calculators over the years. When it comes to scientific calculators there is a vast range to choose from, Casio being at the forefront of those avaliable and often the go to calculators for many students. However, as time progresses even with experience in using the relatively simple Casio-style scientific calculators, according the more complex functions can be a little bewildering.I heard about the FX-911EX approximately a year ago when they were first released in Japan and extremely hard to get hold of. I was amazed by their high resolution display to allows the calculator to display full text rather than abbreviations. For example,

18.7.2020

I have used Casio calculators for many years. My last one has lasted over thirty years and is beginning to show it age.I needed something close to the same functionality but could not find it. Even this one does not match up and is far more fragile but I do like the display and the way it has separated out the various functions. The natural display of fractions and algebraic symbols is a definite plus even if the font is old fashioned. For myself I needed a strong statistical section but proper matrices is missing with what there is being limited to a 4x4. Calculus is missing and not to be found at all. In the real world you need more than this calculator can do so it may well be fine in an exam room but not in the workplace.

29.5.2017

A worthy successor to the Casio fx-991ES PLUS. This is pretty much the best calculator you can get until you reach the point where you need a graphing calculator, which right now means A Level. Anything below - GCSE, Year 9/8/7/etc. - and this is an ideal calculator.As an aside, even at A Level, this makes a great scientific calculator as a companion to a graphing calculator; it's best to take a scientific and graphing calculator into A Level exams.Other improvements over the fx-991 series:* The internals have also been upgraded, so certain operations (e.g. numerical integration) are MUCH quicker.* The look of the calculator is much cleaner* The screen is much higher definition,

22.12.2020

Does the job for GCSE and A-level Maths, in style. Looks good and works well. It has dual-battery (solar and cell) so it will probably last years before needing to change the battery. There are lots of functions that enable you to solve problems that others have to do manually, such as solving for x in an equation. It can convert between denary, binary and hexadecimal, useful in Computer Science but a shame that calculators aren't allowed in CS exams! Had to look in the (very useful) manual to find out the functions of some features.However, a small gripe is that it's missing the "recurring" symbol, for example when you want to write 1/3 as a decimal but you have to input 0.33333 and so on rather than 0.3*.

21.6.2018

Excellent calculator, I bought it because the fx83/85 doesn't do base conversion, however the matrix functions turned out to be very handy.It's actually quite difficult to get to grips with all the functions on this, so I bought a book which was quite helpful, although it didn't cover Bases. I also watched a few youtube videos which sere generally helpfulI haven't really tried the Stats as I was doing a discrete Maths course, apparently you need this for A levels as they no longer supply Stats tables in the exam.It took a while to get used to the new Textbook display, as I was sued to the older decimal style. However once you get to grips with it, I found it really helpful,

12.2.2021

This Casio fx-991EX gives everything a GCSE / A Level maths student needs to enhance the chances of passing the exam with better grades. You can factorise quadratic functions, solve simultaneous equations, solve linear equations, Table feature helps you to plot graphs, You can figure out ratios. You can solve quadratic inequalities. You can do unit conversion and work out prime factors . You can evaluate mean and standard deviations and all other associated statistical parameters. From data you can work out PMCC and regression coefficients. Not to mention all the stats tables inside the calculator for you to work out binomial and normal probabilities. For Further Maths students it helps you with matrices and vector calculations too.

19.6.2020

The fx-991ex is Casio's top scientific calculator and I think that it fully lives upto that high claim.It has a pleasing design and finish, white number keys, metallic function keys and scientific (trig, exp etc) in regular black colour.It has a icon based menu: calculate, complex, base-n, matrix (upto 4x4), vector, statistics, distribution, spreadsheet (upto 5 columns and 45 rows), tables (can compare 2 functions), equation/function (upto 4 unknowns, degree 4), inequality (similar to equation), ratio.I tried it out with some definite integrals and its very fast compared to my older calculators.Final note, its not programmable and cannot graph or do symbolic algebra,

15.4.2020

Note: This is not your typical scientific calculator; it's an upgraded version with many new additional features.In comparison to the typical one, this one can do some of the following:* Find the area under the curve of most graphs (integration)* Find the gradient at any specific point you want (differentiation)* Solve equations including polynomials up to an n value of 4* Matrices* Vectors* Distributions* Etc....I can say this because I actually have your standard scientific calculator and this one. This is why it may come across more expensive so don't buy if you don't need - generally this is a calculator that you would use in university or A-Level maths; anything else,

20.5.2017

This is now the base line for cheap skates, or lazy students, who refuse to invest in a good graphics calculator.I unequivocally recommend that Y12 and Y13 students get themselves a TI-Nspire CX, and LEARN how to use it well. However, a surprising number insist on sticking with the £10 calculator they bought in Y7.Well now you MUST upgrade because the exam boards (so I've read) are no longer going to hand out statistical tables. This does everything that the FX-991ES PLUS does, and a bit more. But, in particular, it will do normal distribution (including inverse lookup), poisson and binomial distributions. So if you are too tight to buy a GOOD GDC then this calculator is excellent value.

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