Step 1:
The first step to converting 531440.9990625 to a fraction is to re-write 531440.9990625 in the form p/q where p and q are both positive integers. To start with, 531440.9990625 can be written as simply 531440.9990625/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 531440.9990625, which in this case is 7. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 531440.9990625/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 531440.9990625/1 each by 10000000:
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 531440.9990625 as a fraction:
531441/1 / 1