I'm in need of isolating the decimal part of a number using maths only, no excel functions or anything like that, but it's proving to be much harder than I thought it would be.
For example, I have the number "XXX.YY" and I want to just have the "YY" part. How would I possibly go about this? I know in Excel I can do "MOD(XXX.YY,1)" but is there anyway of actually doing this with just math?
Let your number $XXX.YY$ be equal to $Z$.
Then the decimal portion of your number is given by $Z - \lfloor{Z}\rfloor$, where $\lfloor{Z}\rfloor$ is the greatest integer less than or equal to $Z$.