Which can be used in combination to represent any number of any size. An older system of representation, still sometime encountered on clocks and other places, is [[Roman numeral]]s, which used certain letters of the [[alphabet]] instead. | Which can be used in combination to represent any number of any size. An older system of representation, still sometime encountered on clocks and other places, is [[Roman numeral]]s, which used certain letters of the [[alphabet]] instead. |