dc --help
BusyBox v1.20.2 (Debian 1.20.2power4+thumb0) multi-call binary.

Usage: dc EXPRESSION...

Tiny RPN calculator. Operations:
+, add, -, sub, *, mul, /, div, %, mod, **, exp, and, or, not, eor,
p - print top of the stack (without popping),
f - print entire stack,
o - pop the value and set output radix (must be 10, 16, 8 or 2).
Examples: 'dc 2 2 add p' -> 4, 'dc 8 8 * 2 2 + / p' -> 16