Step 1:
The first step to converting 638651.0643945 to a fraction is to re-write 638651.0643945 in the form p/q where p and q are both positive integers. To start with, 638651.0643945 can be written as simply 638651.0643945/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 638651.0643945, which in this case is 7. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 638651.0643945/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 638651.0643945/1 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 638651.0643945 as a fraction:
638651/1 / 1