confusing notation on calculating F/X returns

when given Beginning Spot F/X as 100Yen/, and Ending Spot F/X as 125Yen/ What is the “F/X” return in Yen? How do you know when to do 125-100/100 = 25% vs. doing the inverse [1/125 - 1/100] / 1/100 = - 20% I’m asking in terms of the #(the inverse thing), not the sign, which i know is negative since yen depreciated.

foreign exchange??

irregula, I had the same problem. which way to convert to calculate % appreciation. here is what i do now. convert it to domestic currency (you have to any way to calculate both hedged and unhedged returns). change/original investment = % change.