Step 1:
The first step to converting 17781.876820518 to a fraction is to re-write 17781.876820518 in the form p/q where p and q are both positive integers. To start with, 17781.876820518 can be written as simply 17781.876820518/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 17781.876820518, which in this case is 9. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 17781.876820518/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 17781.876820518/1 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 17781.876820518 as a fraction:
142255/8 / 1