You could add "without using multiplication or division" as a less arbitrary constraint. Early microprocessors (and some really cheap microcontrollers still) d

You could add "without using multiplication or division" as a less arbitrary constraint. Early microprocessors (and some really cheap microcontrollers still) didn't have the circuitry. That said a fixed-factor mutiplication can probably be done faster AND [more] precisely as a sum of some shifts. Or many other ways with a lookup table.