how do you type the line over a repeating number?
Try:
OverBar[3333]
Are you looking to use a number like 0.33333... in your code and have it treated as 1/3? Are you using Mathematica or Wolfram|Alpha?
Here is an article about how to write repeating decimals in Wolfram|Alpha:
http://blog.wolframalpha.com/2011/07/27/repeating-decimals-in-wolframalpha/
Repeating Decimals can always be written as a fraction. There is some code for this online already:
http://stackoverflow.com/questions/5200617/how-can-i-make-a-working-repeating-decimal-representation-of-a-rational-number
