Key in values, hitting the Enter key after each one. The operation keys (-/+, +, -, *, /) cause a calculation to be performed automatically, so you don't need to click on the Enter key for those. With an RPN calculator, you put in the values before putting in the operation. So, for example, to calculate 7 + 2, the sequence woud be '7', Enter, '2', Enter, '+'. The calculator would then calculate the result and display it via the result variable. The Backspace (back arrow) key can be used to correct the current value and the Clear key will clear out the stack and result. Additionally there is sine, cosine, tangent, log, square root, second and third power, as well as the new backspace button.
An upgrade will come soon with more functions and keys! Move the stack to left to see 1,4,7,-/+, and clear. Thanks to CrazyCatGuy for: RPN Calculator (Original Project) Thanks to wjholst for: RPN Calculator remix (Project Remixed)