[quote=Mammalia]
How would you even calculate that?
[/quote]

_*_*_*_
One space for each digit.
How many numbers can potentially be in the first space? Seven, since 9009 won't be included.
7*_*_*_
How many in the second? Ten, zero included.
7*10*_*_
How many in the third? It's a palindrome, so it has to match the other. Only one digit.
7*10*1*_
Same as before.
7*10*1*1
70
Therefore, there are seventy palindrome numbers between 2,000 and 9,000. This was in my summer probability segment of my college courses.