Step 1:
The first step to converting 670358.78545758 to a fraction is to re-write 670358.78545758 in the form p/q where p and q are both positive integers. To start with, 670358.78545758 can be written as simply 670358.78545758/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 670358.78545758, which in this case is 8. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 670358.78545758/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 670358.78545758/1 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 670358.78545758 as a fraction:
670359/1 / 1