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Casio FX-991EX Engineering/Scientific Calculator, Black
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- High Resolution Display to view more data like spreadsheets & 4x4 matrix calculations
- Natural Text book display - symbols and numbers appear just as they do in textbook
- Numeric Integration/Differentiation. 552 functions
- Simultaneous and Polynomial Solver
- Solar Powered with Battery Backup (LR44 Button Cell Battery Included)
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Casio Scientific Calculator
A new high-performance scientific with high resolution display increasing the amount of information displayed and super-fast calculation speed for high-stakes testing or for performing the most advanced mathematics.
It’s new high resolution LCD screen allows more information for applications like Spreadsheets and 4X4 matrix calculations. This calculator has a comprehensive set of advanced calculations for integration and differential calculus, along with vector and inequality calculations. For the middle and high school grades, we’ve incorporated basic spreadsheet functionality, ratio and statistical functionality, down to ratio calculation and prime factorization.
No matter what the need, this scientific can do it all! Need graphical representation for data generated by the fx-991EX - no problem! Generate a QR code for your problem, scan the code and immediately see a graphical representation of your data; within a classroom, students can see their collective data in real time with other students.
- General Math
- Algebra I&II
- College Algebra
A high performance scientific calculator with high resolution display increasing the amount of information displayed and super fast calculation speed for testing or performing the most advance mathematics. High resolution LCD screen allows viewing of more information like spreadsheets and 4x4 matrix calculations. This calculator has a comprehensive set of advanced calculations for integration & differential calculus, along with vector and inequality calculations. For middle school, high school and college math courses.
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1) Missing functions: LCM, GCD, Remainder division, Recurring decimals, and Product calculation - I have no idea why it was necessary to remove these important functions, so this is definitely a downgrade and a disappointment! Moreover, it turns out these features are available on some foreign versions of the same calculator, which leaves me wondering why the Casio marketing decided to drop them specifically from the U.S. version.
2) Usability: numbers are displayed in smaller font, which is harder to read; also the shift functions are painful to read on the black, textured, and somewhat reflective background.
At the same time, the new model has several obvious advantages over fx-115ES PLUS, such as:
1) a much faster processor (which is obvious when calculating integrals)
2) a new "QR" feature that can display graphs on your smartphone
3) a new "OPTN" button that can save you time
4) a separate "x" variable button that saves time
5) improved memory recall feature that shows all variables on one page
6) spreadsheet mode
Compared to the leading scientific calculators made by other brands (most notably Sharp and TI), my biggest pet peeve about Casio is that IT LOSES ALL THE HISTORY AS SOON AS THE POWER IS TURNED OFF. This is by far the biggest reason I stopped using Casio at work. As an engineer, I want to be able to return to the same formula I was working on after my calculator turned off due to inactivity. This should be THE most basic feature for any advanced engineering calculator, and I find it mind-boggling that the Casio marketing keeps ignoring it.
Other very useful and time-saving features that I would really like to see in future Casio calculators are: 1) a way to store and recall a few frequently used formulas, and 2) being able to jump to the beginning and end of the formula, e.g. by pressing Shift-Left and Shift-Right.
If Casio addresses my concerns mentioned above, I will be glad to consider this brand again.
"Note: Calculation history data is all cleared whenever you press "ON", when you change to a different calculation mode, when you change the Input/Output setting, or whenever you perform a RESET operation [...]"
"Important: Any time you exit the Spreadsheet Mode, turn off the calculator or press the "ON" key, every input into the spreadsheet mode is cleared."
------ Really, Casio? That's the best you've got? ---------
This calculator has a beautiful screen, it's extremely fast, and it's mathematical chops are very good - many scientific calculators can't handle 4x4 matrices and 4-variable systems of equations, and it's accurate to more places than a ti-36x for integrals, etc. However, on usability, this thing falls flat:
- All history/recall is lost, including spreadsheet data, when changing modes or powering off (which happens automatically after 10 minutes) ... this is pretty much a deal killer for me, moving this thing into the 'unusable' category. Taking a test and your calculator times out? History is gone. Need to do some matrix or vector math? History is gone. Seriously aweful.
- In calculate mode, only one calculation/equation at a time is displayed. Although you can 'rewind' through prior calculations and edit them (until you change modes, at least), it's not a 'scrolling' display - you flip through prior expressions one at a time. TI has achieved this on lesser hardware with the TI-36X, so the fact that Casio can't do it on this obviously very capable hardware platform is kind of pathetic.
- I know it's very Casio, and I didn't factor this into my rating since it's just their 'style', but I'm surprised that Casio is hanging on to the archaic 'mode' concept for things like complex numbers and vectors. Why aren't these integrated into the primary 'calculate' feature? This would be less painful if the various modes retained their data when you switched away from them.
All in all, I'd have given this a four star rating if it retained history between modes and after powering off and had a slightly nicer history scrollback feature, and an easy 5 if it integrated functionality from the stats, matrix, complex, and vector modes into the main 'calculate' mode.
Next time around, Casio, do all of that and I'll be quite happy ... and if you introduce a solar scientific calculator with some basic CAS features (I couldn't care less about graphing, and hope you avoid programmability for the sake of maintaining NCEES acceptance), you'll have a devotee for life.
LaTeX compatible script generated via VPAM, passing resulting to other devices, and graphing via QR code feature is very useful, and maybe unique to Casio; its equivalent capability is found in only expensive, larger and more cumbersome to use USB and Wifi calculators. The Casio website has far more horsepower than a calculator allows so added processing is faster, website provides more appealing graphics, added features, data sharing etc., while keeping the cost of the calculator near than of older models without QR feature. Casio's strategic commitment to education support for decades means its extremely unlikely the website or the QR method of passing results will be orphaned in the future because it requires so little resources to do. Its a win-win for everyone.
CPU is >> 2x faster than the FX-115ES+
Higher resolution LCD easier to see and crisper
Much easier to use constants and conversions
Better build quality than the FX-115ES+
All calculations or equations are lost when powered off, not a big concern in professional use