Calcute

Calcute is a lightweight application that allows users to perform various mathematical operations in a clean environment.
The main window is minimalist and can be moved to any area of your desktop. By default, the program displays a small panel where you are allowed to make the calculations, but you can change its size.
The application offers users the possibility of making basic math operations, such as addition, subtraction, multiplication and division, as well as using trigonometric functions like sine, cosine, tangent and others.
The GUI is divided into two main areas, with the first one displaying the results and the second the mathematical functions. The generated results can be copied to the Clipboard or saved to a plain text file.
The cross-platform program is also able to read information from plain text files, and you can change the number format (decimal, hexadecimal, binary, octal), group digits together, as well as modify the font style and button size.
You can also make the program stay on top of other applications, and this proves to be pretty useful, especially when dealing with multiple tools in the same. Plus, you can maximize the frame to full screen mode. Additional features allow users to clean the results panel and undo their last action.
As it would be expected from such a small utility, it doesn’t eat up CPU and memory, so it doesn’t affect the overall performance of the computer.
To sum things up, Calcute displays the mathematical results very quickly and, thanks to its overall simplicity, it may become ideal for rookies. The portable version of the program can be found here.