Well, first I'm going to begin with converting -.125 into a fraction.
Our first step is to change -.125 into -125/1000. From there, we just simplify it.
-125/1000 divided by 5 gives us -25/200. Divide by 5 again and we have -5/40. Once more, and we arrive at -1/8, which cannot be simplified further.
The next aspect of the question is to change -.125 into a percentage. Well, the conversion for that is quite simple. Take the value and multiply it by 100. That moves the decimal point up two units, and gives you a percentage. For us, -.125 becomes -12.5%.