Step 1:
The first step to converting 654.578449458 to a fraction is to re-write 654.578449458 in the form p/q where p and q are both positive integers. To start with, 654.578449458 can be written as simply 654.578449458/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 654.578449458, which in this case is 9. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 654.578449458/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 654.578449458/1 each by 1000000000:
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 654.578449458 as a fraction:
12437/19 / 1