As an American, this doesn't seem any stranger than our dual-units-of-measure system. One is defined in terms of the other. One is what we (mostly) use locall

As an American, this doesn't seem any stranger than our dual-units-of-measure system. One is defined in terms of the other. One is what we (mostly) use locally, and the other is what we use with anyone from any other country in the world. People living here know from experience and context which system is implicitly attached to a bare number.