Reading? Scanning? ...or... text-to-speech!

Some more thought on go to page.

I think the layout should be two lines (again with my 99 page example):

1-33 34-66 67-99
Back Cancel

It would start with the center range underlined. The Back would not, of course, be available (greyed out?) at the first level but on the subsequent ones. Back and Cancel would be accessed by pressing the down button.

For the number range line the left, center and right buttons would immediately go to the next level whereas the down button would just move down to the Back and Cancel line.

The only special case exception for the end would be needed if the number of pages divided by 3 gives a remainder of 2. You'd have something similar to:

45 __ 46
Back Cancel

The center button would do nothing.