Earlier quoted context omitted.
I agree about clearing up ambiguity. But I'm not convinced that there's a best way to answer it without context. For instance, enter "1%" into Wolfram and it'll tell you it's 1/100. Do the same for 3% and it'll tell you it's 3/100. Now ask it to add those 2 fractions, and it'll obviously give you 4/100 - which it reports can be expressed as 4%. These are supposed to be alternate representations of the same thing, so…
but `+` is polymorphic in the inputs as is `print` just because `print` does one thing doesn't really mean `+` is constrained in the same way
Let's say f(x) gives some alternate representation of x. Then f(3) + f(1) should be equal to f(3 + 1). Under this interpretation, f(3%) = 3/100 etc, so that 3% + 1% = 4%.
But you could certainly argue that the idea of equating 3% with 3/100 is simply wrong. I like it because I like to think of "per" as meaning "divided by", and we generally use it that way when we use units like "metres per second = m/s = ms^(-1)".