These guides cover the practical side of owning a TI-84: error messages, exam rules, resets, and which model to buy. Every exam rule and spec comes from the official College Board, ACT, or Texas Instruments pages.
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TI-84 Error Codes and How to Fix Them
Look up any ERR message, from ERR:SYNTAX to ERR:INVALID DIM, with the keys that fix it.
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Is the TI-84 Allowed on the SAT? Exam Checker
Check any TI-84 or TI-Nspire against the SAT, PSAT, ACT, AP, IB, and GRE rules.
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How to Reset a TI-84 Calculator
Reset settings, RAM, or all memory, and see what each one deletes before you press anything.
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TI-84 Evo vs TI-84 Plus CE
Specs side by side for the 2026 TI-84 Evo and the Plus CE, and whether upgrading is worth it.
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Which TI Calculator Do I Need?
A three question quiz that picks the right calculator for your class and budget.
Find the right guide for your problem
| If this is happening | Start here |
|---|---|
| The screen shows ERR: and a message | Error codes |
| Answers come out in the wrong angle mode or format | Reset to defaults |
| The calculator is frozen and no key responds | Reset guide, frozen section |
| You are not sure your calculator is allowed on a test | Exam checker |
| You are deciding what to buy | Buying quiz |
| You heard about the new TI-84 Evo | Evo vs Plus CE |
Keep your TI-84 working
A few habits prevent most of the problems these guides fix. Charge a TI-84 Plus CE or Evo every couple of weeks, since a dead battery the morning of a test is the most common calculator emergency.
Archive programs you want to keep, so a RAM reset cannot erase them. Update the operating system with the free TI Connect CE software when Texas Instruments releases a new version, especially before an exam season.
Practice without a handheld
Every guide pairs well with the free TI-84 calculator online, which uses the same keys, menus, and error messages as a TI-84 Plus CE. For one task at a time, the online graphing calculator and the TI-84 statistics calculators show the answer and the exact button presses.