OA-991EX Plus Scientific Calculator 552 Functions 2-Line 10+2 Digits Written Display Solar Battery - Ideal for Middle High School Students and Teachers, Black

Excelente

With 550 functions this calculator would be a fine choice for students from middle school to college and into professional work.Keys work well. No missed presses. The included slide on cover protects the keys while not in use or being carried in a backpack . Solar and battery power is a definite plus.Major downside: The faceplate is embossed! This was obviously designed by an "Artsy" person rather than an actual user since the embossing makes it difficult to impossible to read the alternate key symbols in almost any lighting situation.Had to return it! Very disappointed as I really liked it otherwise.

I am quite pleased with this calculator. It comes programed with multiple functions, in some cases going beyond a typical scientific calculator. Vector, matrix, probability, integral, or statistical calculations, this calculator can handle surprisingly many of them. As a primary user of TI calculators, I found transitioning to the Dupota calculator a bit challenging due to the learning curve. As long as the protective buyer is okay with that, this solar calculator is extremely powerful and a great choice.

I can say in full honesty, I spent over a thousand dollars or more maybe two in today's dollars buying calculators in getting my engineering degree. While I'm sure the cost of textbooks even the digital kind are off the charts expensive today, and tuition is ridiculous, one of the main tools for an engineer costs 20 bucks! To get some of the capabilities of this model as I look through the manual, I had to get an HP costing around 400 dollars, probably double that in today's dollars. Yes, most laptops and tablets have a calculator app, some are even scientific, but none come close to what this can do. Plus, it's more portable and convenient, and cheaply replaced if stolen.Advanced features at least from my day include math book notation to display calculus equations for integration with limit, and derivatives. I see it does complex numbers and matrices as well. I paid a lot to have those features in school on my HP, and it helped me through some tough exams in Networks, Calculus and Statistics. The equations you build on top display numerical answers when equating to a number which is then displayed on the bottom. It has two levels of display, and I see it can handle factorials, logs, trigonometric functions, and algebraic expressions. Computer data calculations can be worked out in Hexadecimal, Decimal, Octal, and Binary. Plus, it's not a battery eater. We used to joke when I worked in the Power Company in Houston, that the cheap calculators they gave us were donated by a battery company as they were LED instead of LCD, so they ate batteries like crazy. This uses button cells, backed up by a solar input that works with house lighting to save energy. The only thing I don't see on the keyboard is a set of financial functions. Maybe not the best business calculator, but it probably does them roundabout with 552 functions, I'm sure it has the capability. You'll likely never use everything this can do, but if you need the functions for school, they are likely there. As with my HP, with the complex capabilities, make sure you never misplace the manual. Recommended.

I have 2 kids that are taking Algebra 2. I debated purchasing the pricey graphing calculator, however, I hesitated. They use an online graphing calculator currently and did not seem motivated to switch. When I was in school, the physical graphing calculator was the way to go, so I asked the guidance counselor for input. They stated that students choose what they prefer, and that it is 50/50 on preference. Mine seem to prefer the online version. With testing in the future, I wanted them to have a scientific calculator, as I feel that this would be what is needed most often (not as much needed with graphing), and it would be quicker than accessing the online one. They agreed and have been using this one to get used to it. There are so many features, so it will take time to learn them and I do not think we will ever need them all, but they are good to have. It is a bit overwhelming, so it is fantastic that they include an instruction book.It is extremely lightweight, which is good. However, it does not feel as sturdy as ones that I have used in the past. So a pro to that is less weight, con is possibly less durable. It does have the sliding protective case, so hopefully that will help. I like that it functions with solar power, so less battery replacements. Overall, we are very pleased with this. It rivals the other brands that we have used and is very reasonable in price. With kids having the option of online graphing calculators in school and for testing, they are not as necessary as they were in the past. The need may change in the future for college courses, but so far so good.

Do not recommend this product. It was giving me divisons in fractions instead of decimals and there arent any instructions online on how to change it. Support your product. Waste of money.

This calculator is a useful tool for simple math. The solar and battery operation is reliable, and the display is clear and easy to read. It’s lightweight yet durable. It's easy to navigate all the functions, but this calculator gives some answers in fraction form. Sometimes this wasn’t a problem for me, but it was inconvenient on tests. I couldn't figure out which function converts the fraction to a decimal or if it had a function like that at all.

It got the job done!