The remainder is a fraction (remainder/divisor).
Why don't you use a calculator...for instance, 31/7 is 4 r 3, but it is easy enought to just put 31 divide by 7 in the calc.
I have to solve a proportion, and the answer I come up with has a remainder. I know I need to make the remainder a decimal, but I forgot how. How do I convert the remainder into a decimal?