RPN Calculator

Stack (LIFO)

Stack Empty

Input:

How to Use RPN

What is RPN?

RPN (Reverse Polish Notation) is a mathematical notation where operators follow operands. Instead of "3 + 4", you enter "3 4 +". This eliminates the need for parentheses and follows the natural order of calculation.

How RPN Works

Stack: Numbers are stored in a Last-In-First-Out (LIFO) stack
ENTER: Push the current number onto the stack
Operations: Pop required numbers, calculate, push result back
Natural Flow: No need for parentheses or order of operations

Basic Operations

Addition: Enter "5 3 +" = 8
Subtraction: Enter "10 3 -" = 7
Multiplication: Enter "4 5 ×" = 20
Division: Enter "20 4 /" = 5

Stack Operations

DUP: Duplicate the top stack item
SWAP: Exchange top two stack items
DROP: Remove the top stack item
CLR: Clear the entire stack

Example Calculation

To calculate (15 + 5) × 2:

Enter 15, press ENTER
Enter 5, press +
Enter 2, press ×
Result: 40

Try Sample Calculation

Follow the sequence: 15 ENTER → 5 + → 2 × = 40