Bit late? but hows about how to convert a reccuring decimal to a fraction? (or have i misread the question?)
eg. prove that 0.3 is equal to 1/3
to do this, let x = 0.3333333333...
therefore 10x = 3.333333....
so 9x= 3
divide both sides by 9
x=3/9
x=1/3
[end of proof]
Think im a little late mind.