Is it actually frozen, or just busy? A long calculation shows a busy spinner and the screen sits still. That is not a crash, just the handheld working. Press and hold for a few seconds (or hold ) until a BREAK prompt appears, then cancel the calculation to return to your document. Only if nothing responds at all is it genuinely locked.

Switch it off and on. Still stuck? Press to switch off, wait a moment, then to switch back on. A frozen Nspire is usually a low battery caught mid-calculation, and a power-cycle clears it. If no key responds at all, use the reset button.

The reset button on the back. Turn the handheld over: there is a small recessed reset button near the top. Press it with the tip of a paper clip and hold for about five seconds, then release. It reboots. Unsaved work is lost — anything typed into the Scratchpad or not yet saved to a document — but your saved documents and the operating system are untouched.

Stay out of the Maintenance Menu. Holding , and together while you press opens a hidden menu, and two of its three options are destructive: Delete OS removes the operating system (only a computer with TI-Nspire software can put it back), and Format File System erases every document. The plain reset button already reboots, so there is no reason to open this menu in an exam. If you land in it by accident, choose Reboot — the option that changes nothing — and nothing else.

Prevent it: charge the night before. If the handheld keeps rebooting on its own or will not start, the battery is flat — connect it to a wall charger or dock for at least five minutes before trying again. Charge it fully before every exam so it never gets to that point.