CASIO fx-115ES PLUS 2nd edition vs CASIO fx-991EX CLASSWIZ

The video highlights a few differences between the CASIO fx-115ES PLUS 2nd edition and the CASIO fx-991EX CLASSWIZ.

They are both great calculators for the money (about the same cost in the US). I am not sure why CASIO continues to offer both of them, but there are enough differences that it is worth comparing them before choosing.

My slight preference is for the fx-115ES because of the larger display text, remainder division (mod), GCD/LCM, and a slightly more intuitive CALC/SOVE approach, and a keyboard with marginally better feel. I do wish, though, that it had the faster processor from the fx-991EX.

[leemeister]

Thank you for taking the time to make this demonstration. I just ordered an fx-991ex as a replacement for my 30+ year old fx-991n. The LCD display in the 991n finally gave out. The 991ex has many, many more functions to offer than the 991n, most of which I'll probably never use. However, it is nice to have tools on hand just in case a need does arise or just to play around with once in a while.

I also have an fx-160 that I got in Singapore circa 1980. It is still going strong!

[wistove]

Thank you so much. I have the fx-115ES PLUS and sometimes I have to wait for some seconds for the SOLVE. I've been looking for this SOLVE duration comparison which I could not find from anywhere else than here. Thanks a lot. I am ordering 991 right today.

[czluver]

I picked up the 991 roughly two weeks ago and love it. There's just something about the font that is easy for me to read.

[StressBlister]

Great Comparison.

The different features in different regions has a lot to do with the local education systems. Calculators are allowed in tests, but only if they have or don't have certain features. A good example of this is the TI 30x PLUS and TI 30x PRO in germany... In a few german states, they don't allow some of the features that the pro has, so you have two, nearly identical calculators, except one is missing a few features from the other, to satisfy local education authority rules regarding what is allowed during tests.

[mrkrokogator]

We can make that even a little more complicated: I got the fx-991DE X, DE stands for deutsch/german. This version has the repeating decimal display, GCD/LCM, product function and a few other things. Kind of a combination of the two.
I really like the SwissMicros DM42, I grew up with RPN and that‘s how my mind works.
Greetings from Switzerland!

[jaredrhodes]

I really like the unit conversion menu on the fx-991ex. Freshman year of college I had a Casio with the unit conversion reference numbers listed on the calculator cover but decided to commit the reference numbers to memory since I worried that referencing the calculators cover during tests may raise suspicions that I was cheating with hidden notes on the calculator's cover following another student getting caught doing exactly that.

[deezmaria]

Thankyou so much for this, i used a 991EX and i gave it to my sis and bought a115ES plus and i felt bad about buying the wrong one(i wanted the 991EX) but now i feel way better with my calculator! Thanks again!

[Imurge]

love the ex black look and chrome buttons 🖤 just bought one

[saujanyapoudel]

The spreadsheet mode is such a life saver for me. Its saves me minutes of time spent on doing tabulated calculations. It's my favourite mode to use in an exam

[simonbaker]

Very valuable review, thanks! There is one glaring flaw in both of these calculators, IMO. Older and simpler calculators have a dedicated button for switching from decimal to scientific notation, something I constantly want to do. Instead, now we have the academically useful, but not very practical, S<-->D button to switch from fractions to number representation quickly.

In chemistry, when evaluating significant digits, sometimes you need to align decimal points to determine the sig figs and then need decimal; sometimes you just look at leading digits and want scientific. Also, comparing calculation results to published numbers is tedious if you can't match the notations. Casio should have figured out a quick way to toggle back and forth. I would rather bury the "ENG" notation button (I never use it) in favor of a "Flo<-->Sci" floating-point-to-scientific button. Even adding this feature to the S<-->D choices in a rotating manner might be satisfactory. Any way to implement it with no more than two button presses is needed.

Another feature sorely needed that I cannot find so far is a way to store the solutions to the built-in equation solver for polynomials (Mode | EQN(5)) so that you can continue to calculate with the solution you obtain. Solving a quadratic in X does not store a root anywhere. It would make sense when viewing the solution to be able to exit to Mode 1 after viewing a root of interest and have the result in the X or M or even the ANS variable. Having all the roots saved of course would be even better, but not sure how to do it without more variables.

Otherwise, the fx-115ES PLUS 2nd Edition is a very useful calculator aside from the display lacking enough contrast.

[devdattamanjrekar]

Scott is ... pretty much in love with the Casio ES model 😀

[outofahat]

The Iberia version (Spain and Portugal) of the 991ex has all of those functions from the 115 es too (remainder division, gcd, lcm, intg and reccuring decimal input) it's pretty weird how Casio changes some of their calculators based on region. I think the Japan version also has a periodic table app

[GeoCalifornian]

With all the different versions of the same scientific calc you would think Casio would implement the most basic feature of power-off memory protection to save your calculation history in Comp mode like TI does. Casio could rule the U.S. market.

[DRH-kmhk]

Thank you for the detailed review. I was pondering between getting the es plus vs ex to replace my fx-991w due to the darkened lcd display and one of the main functions I use is the log 10 and thank you for pointing out the location of this key is there (same as my old cal) and that it doesn't rock on the table. I would have probably gotten an EX otherwise and regretted getting it. I'll order an ES plus and save myself money and headache. Thank you so much once again.

[jihademad]

when you realize that all the comments were replied to by Scott Collins

[franciscov.]

Hi Scott, although the video is old, I hope you can see my commend and give me some advice. I'm looking for a replacement of my fx-991s (Bought around 1995 and it was still working ok, but it was stolen from me). That calculator had the particularity that it was really slim. Are these series 991ex, 991es plus 2nd edition, slim? The 991s was, I would say, slim as a current smart phone or even a bit less!

[billmorrigan]

Excellent review. Thanks a lot. I've almost bought the 991 EX due to my ignorance 🙂 The fx-115ES is better because the EX lacks in certain features: Sigma summation is present but the product (pi notation) is gone, hyperbolic functions are gone, modulo operation is gone. Some operations require more key strokes. *For most people the EX is ideal and should be the choice* but those (very few, e.g. mathematicians) who want more serious functionality and less key strokes should opt for the fx-115ES. I mean the EX is a perfect calculator because the operations removed from the EX are not needed for an average student. If you need hyperbolic functions, capital pi, then the fx-115ES is the way to go. For me removal of the above is a huge dumbing down!

[luisramos]

Sometimes the professional certification agencies don't allow some calculators. Example: NCEES known as the National Council of Examiners for Engineering and Surveying. But, what is very strange is that both of these Casio calculators are allowed in these tests.

[nooneinpart]

Had to make this choice today, I ultimately went for the newer FX-991CW with the simplified layout because I thought it looked aesthetically pleasing. The cover clips on instead of sliding, which becomes very loose over time as each slide wears down the bumps that hold the cover in place. Time will tell if I will get tired of digging through menus for more complex stuff 🙃

Definitely weird pricing, both were $20. Even without considering design, the faster, sharper calc just seems like a better deal.

[miguelramos]

Casio Classwiz fx-991EX is good and the others regional versions too, but the best is the vesion of Spain, it has more functions than American version and than others regional version in the world. I recommend check out it, greetings.