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

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.

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.

This calculator has been a great tool for school! The 552 functions cover everything I need, and the two-line display makes it easy to track my calculations. It’s reliable, and the solar battery is a huge plus for not having to worry about changing batteries.

Had to get a non-graphing for a university course. This one fits the bill, sustains small drops, and is pretty comfortable to hold.

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.

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.

It got the job done!