(1/2 digit) - The 1/2 or "half" in describing the resolution of an instrument to make it 3 1/2 digit or 4 1/2 has a mysterious origin. Conventional wisdom has it that it refers to the front digit, which is either a "1", "-1" or OFF and the implementation of that front digit did not require the use of all 8 lines of a 7-segment digital display, but it only takes 4 lines, or half. (It does take 8 lines to implement a 7-segment digit display.) This still leaves the mystery of the 3/4 digit display as in a 3 3/4 digit voltmeter.