Step 1:
The first step to converting 3857.9908042029 to a fraction is to re-write 3857.9908042029 in the form p/q where p and q are both positive integers. To start with, 3857.9908042029 can be written as simply 3857.9908042029/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 3857.9908042029, which in this case is 10. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 3857.9908042029/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 3857.9908042029/1 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 3857.9908042029 as a fraction:
416663/108 / 1