You can navigate directly to a page in your textbook using the page number box, which resides on the Scrubber Bar menu.
To access the Scrubber Bar, tap/click the button at the bottom right.
Hidden Scrubber Bar
Revealed Scrubber Bar
You can see the page number which you are currently on. Tap/click the page number to type the page number you would like to be taken to, then tap/click Return/Enter.