My scientific calculator is a free and great tools for computing, it support these features:
* Support up to 100 input characters
* Input like in textbook
* Support parentheses for input
* Display complicated expression
* Friendly User interface is like in real calculators
* Degree, radian and gradian mode
* Use cursor for navigation
* Memory variables
* M+, M-, memory

Usage example:

* (1+2)(2+1) = 9
* 4!-3! = 18
* ∛(8) = 2
* 2∛(8)+2!+4C4 = 7
* e^2 = 7.389