Upgraded 991ES Plus Desktop Scientific Calculator, Multiview 4-Line Display with Erasable LCD Writing Tablet, Solar Battery Power with Notepad for School

First off, this is NOT a review by a "paid" reviewer, or in exchange for a free product I received. I see quite a few reviews in exchange for a free calculator in this listing, so I suspect the company is new and trying to get the word out about their product.This calculator caught my eye because it appeared to be an more feature-rich version of several recent competitor models that have the write/erase slate (the "e-writer") feature. Disclosure: I'm a die-hard Hewlett-Packard calculator collector, so my preference is always for RPN-based calculators, but I do think highly of the Casio 991ES/EX models, and so I decided to take a chance and check out this one. It's possible this is a legitimate re-badged or Casio-licensed version of the 991ES Plus, sold by ROATEE, but I'm unaware of whether it is or is not, so I can't speak to that here.The calculator arrived in a very nice, sturdy box, reminding me of the kind of quality you get from an Apple product. White cardboard, form-fitted, and well protective. Opening it revealed the calculator and a beefy 72 page manual in very good English (I believe this might be taken verbatim from another manufacturer). This was not your typical single page manual like in most inexpensive calculators. The calculator itself appears to be well made and surprisingly thick and solid. I have a couple of other write/erase slate calculators which are significantly thinner, so it's interesting that this one is much thicker (probably about 15cm closed). It is held closed by a magnet, so the slate doesn't flop around like with others. The slate does not flip around the back, so it lays like a book on your desk. The calculator side contains the stylus in the lower right corner, firmly inserted. The top edge includes the battery compartment and the lock/unlock switch for the slate (more about this in a second). I'm surprised at the reviews who say they couldn't find the stylus or lock switch, because both are pretty obvious, and well called out in the first few pages of the manual. An imprinted legend on the back shows the position for the lock and unlock switch.The slate itself is pretty standard. I think the green "ink" could be a bit brighter, but it's very clear in bright light (classroom), and readable in low light, but a bit harder. The "clear" button is mounted on the calculator side as a round button at the top, above the screen. If the slate is unlocked, then pressing that button instantly clears the slate. If locked, then pressing the button does nothing. This is one of the better reasons to get this calculator; most competitors do not have the lock/unlock feature, and it's far too easy to wipe the slate by accident. This will not happen with this model, and it's really a must-have for this category of device. The electrical connection from panel to panel for erasing the screen is via a small copper flex ribbon cable near the upper hinge. It's possible that over time this ribbon cable could wear out and break, but it's super small, doesn't poke out, and it will likely be fine for life of the calculator.The calculator itself is VERY similar to the 991EX ClassWiz calculator, and functionally IDENTICAL to the 991ES Plus model, in terms of button and function placement. For example, on this version the RCL button is the default (face value), while STO is the shifted function, which is the same as the ES Plus model, whereas the EX model has them swapped. Comparing to the ES model, every button is in the same spot. Compared with the EX model, most are in the same spot, although the top row is a bit different. If you are familiar with the layout of either of the 991ES/EX family, you probably won't even notice a difference. Capabilities notably missing from this model, which are in the EX model, are the spreadsheet feature, the graphic "menu" in the mode screen, the super handy "QR" code feature in the Casio [really one of the best and most powerful Casio features!], more screen lines, more memory, and some additional helpful screens and more functions. 99% of the population, including Casio users, won't notice the missing EX features. I did not have the two-left-parenthesis problem with the keyboard that one user mentioned. The keys themselves are pretty typical for this type of product, and work well, with a sculpted edge to the shape of the keys. No missed or double presses, no super wiggly keys, etc. It's not an HP keyboard, but it's decent enough. :)The surface of the calculator is very similar to the EX model, with the textured matte black surface. The key legend colors are okay, but not super bright (the Casio colors are marginally better). Personally, I think the calculator looks very nice and professional, and has a good feel to it. It's lightyears better than the ES family, which has a semi-glossy black surface and picks up fingerprints like crazy. I'm a bit puzzled why it's so thick, given that virtually every similar model is thinner, but honestly, I think I like a bit of heft to it. It feels substantial and robust in the hand. Maybe it's just because of the stylus storage.My biggest complaint on this model is that the manual refers many features to the "Appendix", which is apparently a separate document that was not included. I'm not sure if that was intentional or accidental, but it is a bit frustrating, because some essential information is in there. For example, if you want to use the Conversion feature, you must know which conversion equation you want, by number [1-40]. These are listed in the Appendix document, and NOT in the manual. You CAN look them up online, or refer to a Casio manual, but it's not convenient. Same for the Constants, but at least they are listed by name (not number) in the supplied manual. In the grand scheme of things, this isn't a deal killer, and anyone reading this and thinking about getting it shouldn't be deterred by the lack of the Appendix. Note: the Casio ES Plus lists them on the attached hard cover, while the EX model has a set of menus grouped by function names. On the ROATEE, you're going to have to write down the numbers for each factor somewhere or keep a legend if you use those frequently.Basically, this is a clone of the Casio ES Plus model, and shares a majority of the EX functions. I can live without the Spreadsheet feature, which is honestly clumsy in a calculator form factor, of the EX, but I will always miss the QR code feature. Alas, you can't have everything, and I suspect that feature is copyrighted/trademarked by Casio, which would explain why it's not included. The rest of the differences from the EX are fine as far as I'm concerned, so other than these two small omissions, and the missing Appendix, there is no reason to pass on this calculator. It's excellent for any non-graphical needs, from middle through high school. Price-wise, it's more than the original, but then again you get a cool slate for taking notes and writing down intermediate answers, while still having access to all the same functions you need and like from the original.Overall, I give this a thumbs up, and hope to see more from this company. Especially if they ever would consider producing an RPN edition for all of us math nuts who love RPN. :) Well done, ROATEE!

I'm a professional engineer that still uses an HP48G every day. There has never been a better calculator. Having said that, my Son, who is studying EE (Electromagnetics this semester) asked me to get him a "new" calculator, specifically a TI84.He had previously used a TI83, and was familiar with the way it functioned. The problem is The TI84 (and 83) do a very bad job handling vectors. I'm not sure its possible to easily get the cross product between 2 3d vectors (other than solving for the determinant of a 3x3 matrix). THIS calculator does so pretty easily.In Complex number math, it switches between Rectangular and Polar coordinates pretty easily.I've only been playing with the calculator for a couple of hours, but so far it seems well suited for Vector Ops as well as complex number math. I thought the HP35s would be a good choice, but it is completely inadequate where vector ops are concerned.If you really want the best tool for this kind of problem (or any problem for that matter), go to EBay and pick up an HP48G, or just put an emulator on your phone!

Got this for my daughter's college class for C&C. She loves it! Great on the go no need for paper or pen, it has you covered. The way it closes protects it in your book bag, purses or anywhere you wish it keep it. Besides my daughter loves when she uses it, everyone is quick to ask..... " where you get that and how much? " If you need or want one, get this one. You will not be sorry!!😃

Love this calculator! My student had it and he told me about it! I use it at home and when I am out to calculate tips for people who serve me as well as calculating my budget expenses at home! Easy to use! Love the place to do calculations on the right side!

Llegó bien y funciona muy bien, el detalle de la pantalla para operaciones está genial, funciona muy bien, un poco cara pero lo vale