Step 1:
The first step to converting 12960.138512649 to a fraction is to re-write 12960.138512649 in the form p/q where p and q are both positive integers. To start with, 12960.138512649 can be written as simply 12960.138512649/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 12960.138512649, which in this case is 9. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 12960.138512649/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 12960.138512649/1 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 12960.138512649 as a fraction:
90721/7 / 1