Step 1:
The first step to converting 405972986.65125 to a fraction is to re-write 405972986.65125 in the form p/q where p and q are both positive integers. To start with, 405972986.65125 can be written as simply 405972986.65125/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 405972986.65125, which in this case is 5. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 405972986.65125/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 405972986.65125/1 each by 100000:
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 405972986.65125 as a fraction:
405972986/1 / 1