So, I am not 100% sure why it does this, but I have a clue, and *IF* I am right, this will work.
I think it does this because you multiplied by 0.2. The general rule for a multiplication or division equation is to report the largest number of decimal places in any single variable. Your 0.2 is causing the .0 to appear. Therefore, let’s get rid of it.
Instead, try 30,000 * 20 / 100
see what happens.
good luck!