 When simplified, it equates to "n" pins being able to drive "n"2 − n segments or LEDs.Traditional multiplexing takes many more pins to drive the same number of LEDs; 2"n" pins must be used to drive "n"2 LEDs (though a 1-of-"n" decoder chip can be used to reduce the number of microcontroller I/O pins to formula_1).If the number of LEDs is known, then the previous equation can be worked backwards to determine the number of pins required.