>>1327124190 is less than 100 so 10% of 90 is less than 10% of 100 too.
The price would have to go up 10% of 100 to go back to being 100.
The false expectation of the same result is because it's two different "10% of X" statements abbreviated to "10%" and the part that makes it more clear there's a difference ("% of X") isn't explicitly spelled out so you just see "10%" twice and infer the second one will be an equal and opposite increase to the initial decrease.
