Step 1:
The first step to converting 598.405636421 to a fraction is to re-write 598.405636421 in the form p/q where p and q are both positive integers. To start with, 598.405636421 can be written as simply 598.405636421/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 598.405636421, which in this case is 9. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 598.405636421/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 598.405636421/1 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 598.405636421 as a fraction:
22141/37 / 1