Step 1:
The first step to converting 10398.900624518 to a fraction is to re-write 10398.900624518 in the form p/q where p and q are both positive integers. To start with, 10398.900624518 can be written as simply 10398.900624518/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 10398.900624518, which in this case is 9. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 10398.900624518/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 10398.900624518/1 each by 1000000000:
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 10398.900624518 as a fraction:
103989/10 / 1