Hi Anna,

There is not currently a way to skip to a later section of one of the full-length practice tests. The purpose of this is to be able to most accurately simulate the real test by completing the sections in the order they appear on the real exam.

You may also want to add your voice to this older thread: https://khanacademy.zendesk.com/hc/en-us/community/posts/360055090491-Please-stop-locking-the-math-sections-on-the-full-length-practice-tests-

Thanks for posting!