Step 1:
The first step to converting 20520.431701856 to a fraction is to re-write 20520.431701856 in the form p/q where p and q are both positive integers. To start with, 20520.431701856 can be written as simply 20520.431701856/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 20520.431701856, which in this case is 9. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 20520.431701856/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 20520.431701856/1 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 20520.431701856 as a fraction:
143643/7 / 1