There is not much that can be done to figure out how to write 0.0277777778 as a fraction, except to literally use what the decimal portion of your number, the .0277777778, means.
Since there are 10 digits in 0277777778, the very last digit is the "10000000000th" decimal place.
So we can just say that .0277777778 is the same as 0277777778/10000000000.