Step 1:
The first step to converting 42120.880000064 to a fraction is to re-write 42120.880000064 in the form p/q where p and q are both positive integers. To start with, 42120.880000064 can be written as simply 42120.880000064/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 42120.880000064, which in this case is 9. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 42120.880000064/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 42120.880000064/1 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 42120.880000064 as a fraction:
336967/8 / 1