Step 1:
The first step to converting 161640.9909 to a fraction is to re-write 161640.9909 in the form p/q where p and q are both positive integers. To start with, 161640.9909 can be written as simply 161640.9909/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 161640.9909, which in this case is 4. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 161640.9909/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 161640.9909/1 each by 10000:
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 161640.9909 as a fraction:
161641/1 / 1