how do you type the line over a repeating number?

Questions
1

how do you type the line over a repeating number?

2

Try:

OverBar[3333]
3

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:

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