Step 1:
The first step to converting 531.51389396659 to a fraction is to re-write 531.51389396659 in the form p/q where p and q are both positive integers. To start with, 531.51389396659 can be written as simply 531.51389396659/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 531.51389396659, which in this case is 11. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 531.51389396659/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 531.51389396659/1 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 531.51389396659 as a fraction:
18603/35 / 1