Step 1:
The first step to converting 643413189.21468 to a fraction is to re-write 643413189.21468 in the form p/q where p and q are both positive integers. To start with, 643413189.21468 can be written as simply 643413189.21468/1 to technically be written as a fraction.
Step 2:
Next, we will count the number of fractional digits after the decimal point in 643413189.21468, which in this case is 5. For however many digits after the decimal point there are, we will multiply the numerator and denominator of 643413189.21468/1 each by 10 to the power of that many digits. So, in this case, we will multiply the numerator and denominator of 643413189.21468/1 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 643413189.21468 as a fraction:
643413189/1 / 1