Step 1:
The first step to converting 640695.7640625 to a fraction is to re-write 640695.7640625 in the form p/q where p and q are both positive integers. To start with, 640695.7640625 can be written as simply 640695.7640625/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 640695.7640625, which in this case is 7. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 640695.7640625/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 640695.7640625/1 each by 10000000:
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 640695.7640625 as a fraction:
640696/1 / 1