Step 1:
The first step to converting 9890.9981720072 to a fraction is to re-write 9890.9981720072 in the form p/q where p and q are both positive integers. To start with, 9890.9981720072 can be written as simply 9890.9981720072/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 9890.9981720072, which in this case is 10. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 9890.9981720072/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 9890.9981720072/1 each by 10000000000:
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 9890.9981720072 as a fraction:
9891/1 / 1