STACK
Empty stack — enter a number, press Enter
HISTORY
Operations appear here
CONSTANTS
MEMORY REGISTERS
No entries stored
QUICK REFERENCE
Enter Push number to stack
+ - * / Pop two, push result
Swap Swap top two
Dup Duplicate top
Rot Rotate top 3
Drop Remove top
Backspace Delete char / drop
Type expressions directly:
"3 4 +" → push 3, push 4, add
"pi 2 *" → push π, push 2, multiply
"3 4 +" → push 3, push 4, add
"pi 2 *" → push π, push 2, multiply