This answer just prompted a question, which I've wondered about a few times when answering challenges in esoteric languages:
For some esoteric languages, the only means of input/output is reading and writing individual bytes from STDIN to STDOUT, and interesting golfing of numeric challenges is near impossible with decimal input, since 80% of your code will be implementing
If a challenge specifies that a program should take a number as input, can that number be taken as the value of a byte read from STDIN? The same question applies to output (although answers may of course address these two parts individually and with differing opinions).
For the purpose of this question, please assume that the limitations on the range of inputs/outputs is not an issue for the challenge in question.