Is there a simple term to describe the non commutative property of decreasing and increasing a value by some X percentage?

Question

I.e., $100 decreased by 20% requires an increase of (1/(1-0.2))-1) to return to $100. Is there a simple name to refer to this?

Answer 1

Well, in math terms, it's the reciprocal. A 20% drop (80% of original value) needs a 25% increase to break even. .8 and 1.25 are reciprocals.