Simplified calculator built in react.
While you're click buttons adding or subtracting numbers, 
maths operations are done and the result desplayed beneath.
At the same time number of your clicks is counted and this number cannot be reset.
Clicking reset button resets the maths part only, 
so you can start your operations again and again but be careful and mind your processor ability to make big number of operations in short time ;-)

The settings used for this project are suitable for development only and very convenient for learning because they use in-browser babel compiler.