Here's why:
* Complexity: Simple pop-up books might only have a handful of pages, while more intricate ones can have dozens.
* Story Length: A longer story will naturally need more pages.
* Theme: A pop-up book focusing on a specific topic might have fewer pages but with elaborate pop-ups.
So, there's no one-size-fits-all answer. You could find a pop-up book with just a few pages, or one with 30 or more!