Stack, not lines
Push numbers and let operators act on them. Fast, keystroke-efficient, and ideal for long chained calculations.
Exact & symbolic, in 2D
Fractions, radicals, multiples of π and their sums stay exact — 4√2, π/2, √2 + √3, (1+√2)² = 3+2√2 — rendered as stacked fractions and radicals, with the decimal (≈) beneath.
Familiar keys
Every operator key keeps its printed symbol. Only the stack moves get new homes on keys unused in RPN.
See it in action
3 EXE 6 ÷ → 1/2 exact fraction 2 EXE √ → √2 exact radical 8 EXE √ 2 × → 4√2 simplified 2 √ 3 √ + → √2 + √3 sums stay exact π EXE 2 ÷ → π/2 rational multiple of π 5 ! → 120 exact factorial
Subtraction and division are level 2 (op) level 1. Entered the operands in the wrong order? Press ( to SWAP the top two.
Key map
Operator keys apply to the stack; RPN-useless keys become stack operations.
↳ Open the interactive keyboard map
| Key | Action |
|---|---|
| 0–9 . EE | type a number |
| EXE / OK | Enter — push input, or duplicate level 1 if empty |
| ⌫ | delete a character, or drop level 1 when the input is empty |
| shift+⌫ | clear the whole stack |
| + − × ÷ ^ | add, subtract, multiply, divide, power |
| x² √ eˣ ln log | square, square root, exp, ln, log₁₀ |
| sin cos tan (+shift) | trigonometry and inverse trigonometry |
| π | push π |
| ( ) | SWAP / OVER |
| shift+− | NEG (change sign) |
| shift+÷ | INV (1/x) |
| Ans | →Dec — decimal approximation of level 1 |
| shift+↑ / ↓ | roll the stack up / down |
| shift+. (!) | factorial |
| Toolbox | stack menu: ROT, PICK, DUP, RAD/DEG… |
Install
1. Download
Grab rpn-vX.Y.Z.nwa from the latest release.
2. Connect
Open the NumWorks app uploader and plug in your calculator.
3. Upload
Send the file. The app appears at the end of the home menu.
External apps run in a sandbox and can't reuse the built-in symbolic engine, so RPN ships its own numeric core: exact rationals for + − × ÷ and integer powers, decimals for everything else.