Lets say we have the following currency pair: EUR/USD @ 1.17 : No need to mention that it is read as the following : 1€ = 1.17$.
Mathematically speaking is it correct to say that EUR is the numerator [top number in fraction] and USD is the denominator[bottom number in fraction]? I know that this might go beyond the mathematical nature of the question but can we assume the first item is always the numerator and the second item is the denominator when we are given an exchange rate?