The important point is that math, like English, is a language, and it is important that you use it with the precision you intend, to convey what you need to. Clarity can be vitally important, to assure that one thing works as intended with the next....
If the tower cleared you to land on runway "E", you'd expect a final approach heading somewhere between 045 to 134 degrees. Landing on runway 09, conveys much greater precision of heading. Runways aren't "090", cause no GA heading indicator is that good!