I frequently see newer cars and trucks, which, instead of having a keyhole to gain entry, have an electronic combo pad instead (or in addition to the keyhole). Each button has two numbers on it, instead of one, like this:
[0-1] [2-3] [4-5] [6-7] [8-9]
My question is why do the buttons have 2 numbers each - i.e. the first button represents the numbers 1 and 2. It seems like one button covering two numbers is just not necessary. If I were to sit in front of the car, it is simply a matter of pushing the buttons in the correct order to unlock the car. The labeling of the buttons could be in a foreign language for all I care.
My guess is that the auto makers do this to say their locks are ultra safe because they have x number of (mathematical) combinations since each button has two values, while they are really limited to their number of physical combinations, which would be a lesser number.