Help

0.5=5/10=1/2

0.05=5/100=1/20

0.005=5/1000=1/200

etc. 

Put the decimal over the power of ten that corresponds to the place of the last digit.

0.0005= 5 in the ten thousandths=5/10,000=1/2,000

It won't always be so cut and dry, like=

0.31=31/100=can't be simplified further

Or repeating decimals you probably won't get lke:

0.33 = 1/3

For those, you just have to remember the repeating decimal values of certain fractions, or you can just do the math. 

If it terminates, put it over 10^x+1, x=# of decimal places

If it repeats: (repeating digits)/9(\(\sum{10^{-y}}_{y=1}^{x}\)), x= # of repeating digits

If it does neither, raise it to a power and then try

If it's a whole number, put it over 1

If it's \(\pi\) or \(e\) put it over 1