This calculator uses Reverse Polish Notation (RPN).
That means that you first push numbers on a stack and then you select the operation to perform.
For example, to compute (100 + 200) / 3, you would type 100, Enter
(to push the current number up the stack), 200
(the stack now contains 100 and 200), +
(to add the top two stack entries, often called x, 200, and y, 100, together,
remove them and leave the result on the top of the stack, as x), 3
and finally /
(to divide y, 300 by x, 3).
Note how you no longer need parenthesis, nor an equal sign.
Even a memory register is not really necessary.
Additionally, there are a number of stack manipulation operations, such as
switching x and y, dropping x and rolling the stack downwards or upwards.
The display shows the top 4 stack positions.
This is an open-source project. See the GitHub repository
https://github.com/svenvc/rpn_calculator
for more information.
