When time is called, that section is closed. Finishing Reading early does not let you go back to Math. Section clocks are in how long the ACT is.
Use leftover minutes now
Review unanswered and flagged items before you submit, in don't submit early. Hide the on-screen clock if it is eating attention, in hide the timer.
Format choice is in digital or paper.
The bottom line
One-way doors. Spend leftover time in this section, not the next.
Start practicing
Start with a free diagnostic, then drill your weak spots with 15-question quizzes and track how you're doing across Reading, English, and Math. Compare plans whenever you're ready to go further.
This article offers general ACT prep guidance. The ACT can change from year to year, including its format, scoring, policies, test dates, and fees, so always confirm the latest details on the official ACT website at act.org before you make decisions. ACT® is a registered trademark of ACT, Inc. thirty-six is not affiliated with, endorsed by, or sponsored by ACT.