Find r if the equation is y=6(1.02)^n

Example:
0.24
The decimal is in the hundredths place, so you would place it over a hundred, like so:

Then, just simplify how you would with a regular fraction.
The fraction would then be 

Example 2:
0.4
It's in the tenths place.
Place it over 10, like this: 
Simplify it like a normal fraction. It's now 

Example 3:
1.45
There's now a whole number.

Ignore the whole number (1) and simplify.
The fraction when simplified is 

Example 4:
1.6
Whole number and tenths place.
Do the same. The fraction would be 
Ignore the whole number again and simplify.
The fraction is now 

I hope this helped you on converting decimals to fractions and mixed numbers then simplifying them! :-)