Step 1:
The first step to converting 609.78999999535 to a fraction is to re-write 609.78999999535 in the form p/q where p and q are both positive integers. To start with, 609.78999999535 can be written as simply 609.78999999535/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 609.78999999535, which in this case is 11. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 609.78999999535/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 609.78999999535/1 each by 100000000000:
Step 3:
Now the last step is to simplify the fraction (if possible) by finding similar factors and cancelling them out, which leads to the following answer for 609.78999999535 as a fraction:
11586/19 / 1