Some time back a prize of $10k dollars was offered for doing something. After the prize was awarded, a further competition was announced, with a prize that would be “five times more than” the first prize.
So - if you won the second competition, what would you expect your winnings to be?
If I understand the question correctly there are two possible answers.
Well, heck there are a lot of potential possible answers, including “-5”, “Tony Stark” and “red”, but if I limit my possibilities to sane answers (stand away from the post button, Doctor Skald) then I get either 50,000 or 60,000 dollars depending upon how you parse the sentence.
When normal people - who are not hyperaware of words and shades of meaning - use “five times more than” they mean “x times 5”.
You can possibly twist that into meaning, “will add 5x as much to the original prize” but that has near zero probability in ordinary speech or writing.
The “more than” in the phrase in the OP is extraneous. “Five times the original prize” is more accurate and clearly what was meant. I don’t think “five times more than” has a clear definition arithmetically speaking.