CasioCasio fx-991CW– Advanced Scientific Calculator with High-Res 4-Tone Display | Natural Textbook Display | 540+ Functions, Numeric Calculus, Matrix Solver | Ideal for Engineering, Science & Exams

Exelente! La compré para mi hija a usar en la universidad

Love it

Amazing Calculator, has a lot of functions suitable for engineering applications and very easy to use, the buttons are so cool and it looks amazing

Excelente calculadora.Tiene todas las funciones necesarias, realiza matrices de hasta 4x4, integrales, derivadas y demás, el único inconveniente es que si la quieres poner en español no puedes, solo viene en inglés, aunque no es un gran impedimento, su uso es muy intuitivo. No se necesita un gran nivel de inglés para usar todas sus funciones.

There are three calculators that are of roughly the same price that are solar-powered scientific calculators. They are now the casio fx-991CW (previously the casio fx-991EX), the Sharp EL-W516T, and the TI-36X Pro. The fx-991CW [henceforth CW] is basically a user interface change from the fx-991EX [henceforth EX], with, as far as I can tell, no useful new functions and a slower (although perhaps easier to navigate) interface. The only functional additions are a dice roller and a coin flipper program, neither of much utility for the CW over the EX.[From my review of the casio EX, though the same applies to the CW for the most part:All of the calculators are going to work, but the casio [EX] has the highest resolution screen and fastest processor. A definite integral on the casio [EX} is often instant and is at least 5x faster than the same calculation on the TI or Sharp calculators. The casio [EX] calculator also keeps square roots of values more consistently, allowing you to get exact answers. The casio [EX} has all of the features that you'd expect from a scientific calculator except a GCD and LCM calculator. This is not a big deal to me, because the casio [EX} does prime factorization which allows you to get these quite easily, but it is annoying that they didn't implement them nevertheless.]The casio CW still clears the memory of recent calculations whenever you switch modes or the calculator turns off [the same as in the ex], which I find annoying. This means that if you wanted to keep a value for the next time you turn it on, it simply isn't possible. Again, the same as the ex, the CW answer button is programmed to only keep the last value in the stack. (So if you did 2+1=3, and then put in 2+2=4, then went back to see 2+1=3, and typed +2 (Ans would be inserted for you) you would find 6, not 5.) So if you would like to use a previous result you have to scroll to it and enter it again or edit the equation from there. On a more negative note, the CW has reprogrammed the power of 10 button (commonly e or E button) such that it does not take operator precedence on the number preceding it. This means that if you type in 10/2 and get 5 then hit divide by 1E3 [E corresponding to the x10^[] button, which will show up as Ans÷1x10^3 on screen], you will get 5000 and not .005. This is contrary to the use of the power of 10 button and the ex and every other calculator handles this correctly (that is, it doesn't just treat the power of 10 button as a regular multiplication).More generally, the CW is actually noticeably slower than the EX at doing integrals. It's still fast compared to the sharp and TI counterparts, but no longer as outstanding. The CW has also done a total keyboard layout change, and relegated many functions to the catalog button. I can live with such changes, though it takes several more button presses to achieve results. The format key is somewhat annoying because you can no longer default to engineering format, but it is at least straightforward. The buttons themselves are nicely put together at least, and I actually like the more subdued look of the CW compared to the EX.Overall, any of the calculators will work, but the casio EX is the fastest with the CW having the best looking screen. I prefer the EX over the CW, but either is faster than the TI36X Pro or Sharp EL-2516T. If you have an EX, I'd say stick with it, as it has all the same functionality (with the bonus of implementing the power of 10 button correctly). A TI36X Pro is probably now the best bet if the power of 10 is make or break for you and you cannot get a reasonably priced EX.

Como todo lo Casio , exelente producto ....

I love this calculator! Definitely a little better and contains more functions than your average scientific calculator. Easy to use. Absolutely no complaints.

Fantastic product. Fast and easy to use…