For example, 1/3 is fairly easy as 3 repeats from the first decimal point. But suppose the number is 12.345678678678678... How can one efficiently ask Mathematica to return {6,7,8} in such a case?
See http://reference.wolfram.com/language/ref/RealDigits.html
In[2]:= RealDigits[4111111/333000] Out[2]= {{1, 2, 3, 4, 5, {6, 7, 8}}, 2}
Just a slight modification to ilian's post, if all you wanted was the repeating digits
Last[First[RealDigits[4111111/333000]]]
Paul.
