This is a very simple calculator, allowing basic arithmetic operations.
It takes two numbers and one operator at a time to compute the result, then display the result on the screen as the first number for the next operation, just like what it is done on a normal calculator.
The calculator rounds up two decimal places for multiplication and division operations. However, I didn't handle the case where the result is too large that it exceeds the border of the display screen. I might work on that and add some new features in the future.
I tried some fancy styling in css and it seems to work well. I slightly darken the color of buttons and scale it by modifying the hover attribute of those classes. Feel free to check out the source code for details.
Have fun playing with it!