RPN Calculator

data stack

Push it real good
DUP DROP SWAP

user-defined functions

documentation

Put a number into the textbox and hit the button to push it onto the stack.

Put an operator into the textbox, and hit the button to perform the operation on the first two items of the stack.

DUP duplicates the first item.

DROP drops the first item.

SWAP swaps the first and second items

Any function or constant on the JavaScript Math object can be used. For example, try sin or PI, by themselves, without typing Math.