# dc > An arbitrary precision calculator. Uses reverse polish notation (RPN). > See also: `bc`. > More information: . - Start an interactive session: `dc` - Execute a script: `dc {{path/to/script.dc}}` - Calculate an expression with the specified scale: `dc --expression='{{10}} k {{5 3 /}} p'` - Calculate 4 times 5 (4 5 *), subtract 17 (17 -), and [p]rint the output: `dc --expression='4 5 * 17 - p'` - Set number of decimal places to 7 (7 k), calculate 5 divided by -3 (5 _3 /) and [p]rint: `dc --expression='7 k 5 _3 / p'` - Calculate the golden ratio, phi: set number of decimal places to 100 (100 k), square root of 5 (5 v) plus 1 (1 +), divided by 2 (2 /), and [p]rint result: `dc --expression='100 k 5 v 1 + 2 / p'`