What you are seeing is Casio fx-991 EX calculator, which is alternatively known as Casio Classwiz. This is a superb non- programmable calculator, that means you can use it in most of the competitive exams. If you are a lazy person and don’t like to read a long article, then please watch the review video I made:
The feature that I like most of this calculator is, its smoothness. You can really do some fast calculations in it. The key buttons are not like conventional one. Its really smooth and ease to use.When you are attending any competitive exams, you must use this calculator to run fast.
Second feature is the QR code feature. You can get total calculation from the calculator to your mobile app.And also if there is a quadratic equation, you will get detailed graph.
This calculator also provides the opportunity to calculate various inequalities which you may not find in other conventional calculators.
There are many form of inequalities, from 2 polynomials to 4. All of them can be solved in a minute.
Third feature is that it charges automatically when there is a bit of light. The best option is to charge it in the sun light. When it gets a bit of light, display gets brighter. Solar charge will ensure the longer battery life. Display is also super cool.
Other features are totally simillar to the regular scientific calculator. All the operations including tan, sin, cos, integral and differential operations are available. But, as you know, most of the old casio calculator takes lot of times to do integration. But this is really a fast one in this case.