Step 1:
The first step to converting 400646.78366003 to a fraction is to re-write 400646.78366003 in the form p/q where p and q are both positive integers. To start with, 400646.78366003 can be written as simply 400646.78366003/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 400646.78366003, which in this case is 8. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 400646.78366003/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 400646.78366003/1 each by 100000000:
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 400646.78366003 as a fraction:
400647/1 / 1