Step 1:
The first step to converting 8451.9908455728 to a fraction is to re-write 8451.9908455728 in the form p/q where p and q are both positive integers. To start with, 8451.9908455728 can be written as simply 8451.9908455728/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 8451.9908455728, which in this case is 10. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 8451.9908455728/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 8451.9908455728/1 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 8451.9908455728 as a fraction:
921267/109 / 1