Step 1:
The first step to converting 551010780.78415 to a fraction is to re-write 551010780.78415 in the form p/q where p and q are both positive integers. To start with, 551010780.78415 can be written as simply 551010780.78415/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 551010780.78415, which in this case is 5. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 551010780.78415/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 551010780.78415/1 each by 100000:
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 551010780.78415 as a fraction:
551010780/1 / 1