Step 1:
The first step to converting 873.9812128435 to a fraction is to re-write 873.9812128435 in the form p/q where p and q are both positive integers. To start with, 873.9812128435 can be written as simply 873.9812128435/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 873.9812128435, which in this case is 10. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 873.9812128435/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 873.9812128435/1 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 873.9812128435 as a fraction:
46321/53 / 1