Step 1:
The first step to converting 128991192.12345 to a fraction is to re-write 128991192.12345 in the form p/q where p and q are both positive integers. To start with, 128991192.12345 can be written as simply 128991192.12345/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 128991192.12345, which in this case is 5. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 128991192.12345/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 128991192.12345/1 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 128991192.12345 as a fraction:
128991192/1 / 1