The fraction function on calculators

[MaxManus]

My TI 83 plus has a function called "Frac" which makes decimal numbers into fractions. If I have 0.33333... on the screen and press Frac the calculator returns 1/3. My question is how does this function work.

 

[MATLABdude]

Probably the same way you do it by hand (with appropriate logic / for whether a number repeats or doesn't):
http://www.mathwizz.com/algebra/help/help16.htm

 

[MaxManus]

Thanks