I would first like to thank you because it is the simplest and most effective calculator I have found but some improvements need to be added.
1- the miller separator is very important to properly identify and read the numbers and amounts
2- we don't need a keyboard on the interface which hides the web page since we have the keyboard or give us the option to hide it
3- we need the instant result which is displayed by typing
4-We need a small bar which always remains displayed if we click on the web page
thanks

The buttons don't work