See bug 52037. This is to address the fact that the installer can't do basic math :-(
I don't understand this bug. Maybe you're tired from entering and modifying a bunch of bugs, but this one really is inadequate.
Bug 52037 was designed for the buttons, this was designed for the math. However dveditz explained the math in 52037, so i'm resolving this as a dupe. *** This bug has been marked as a duplicate of 52037 ***
removing dependency, verifying.