Step 1:
The first step to converting 638550.7809486 to a fraction is to re-write 638550.7809486 in the form p/q where p and q are both positive integers. To start with, 638550.7809486 can be written as simply 638550.7809486/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 638550.7809486, which in this case is 7. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 638550.7809486/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 638550.7809486/1 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 638550.7809486 as a fraction:
638551/1 / 1