The NextPage Buttons plugin lets you break up your post or page content into pages. This is functionality that was once in WordPress core, but was removed. So use this plugin with the knowledge that it might not work forever. It is easy to use, though it is a manual procedure. Scroll through your page and post, and where you want to break into a new page, simply click the “Next Page” icon pictured below:

Your content will be broken up into pages, and at the bottom of each page you will see navigation buttons like these:

Clicking on “Single Page” will break the pagination and display all your content on one page. You can scroll throughout. But clicking back on a page number will reverse this, and break your content into pages.