Step 1:
The first step to converting 643939.7847297 to a fraction is to re-write 643939.7847297 in the form p/q where p and q are both positive integers. To start with, 643939.7847297 can be written as simply 643939.7847297/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 643939.7847297, which in this case is 7. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 643939.7847297/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 643939.7847297/1 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 643939.7847297 as a fraction:
643940/1 / 1