TI-89 calculator
Hacker ApprovedRanked 2 of 21 calculators by recommenders
People recommend it for covering basic and advanced math with a built-in CAS and long battery life, though critics warn it let some students skip learning the material.
People recommend it for covering basic and advanced math with a built-in CAS and long battery life, though critics warn it let some students skip learning the material.
39 people gave an opinion
- recommend it
- 31
- criticize it
- 8
- approval share
- 79%
Recommended in 8 of 13 months
- November 2025: recommended
- December 2025: recommended
- January 2026: not recommended
- February 2026: recommended
- March 2026: recommended
- April 2026: recommended
- May 2026: recommended
- June 2026: not recommended
- July 2026: not recommended
- August 2026: recommended
- September 2026: not recommended
- October 2026: recommended
- November 2026: not recommended (month in progress)
Owned for 28 years
Median of the 4 owners who said how long they have had it.
Each square is one year.
Why it carries the badge
- 31 people recommend itNeeds 10 or more, met.
- 3.9 recommenders for every criticNeeds 2 to 1 or better, met.
- Recommended in 8 of 13 monthsNeeds 4 or more, met.
The same three rules apply to every product, and the badge can’t be bought. How the badge works
What people say about it
The reasons people give, with the number of comments that give each one. Open a reason to read what they said.
Why people recommend it
Each mark is one comment
Helped with exams and homework
“It was really handy for checking my work and for working on components of problems.”
Comment from 11 Oct 2026 in “FlowCE: Calculus on your TI-84 Plus CE” “It was utterly essential for solving problems in a reasonable amount of time.”
Comment from 21 Apr 2026 in “College instructor turns to typewriters to curb AI-written work” “loaded a periodic table on it and used it on my high school chemistry exam”
Comment from 2 May 2026 in “Ti-84 Evo” - Comment from 2 May 2026 in “Ti-84 Evo”
- Comment from 2 May 2026 in “Ti-84 Evo”
- Comment from 2 May 2026 in “Ti-84 Evo”
Covers basic and advanced math
“It hits the sweet spot for me in terms of completely covering basic and advanced features I would need from a calculator.”
Comment from 3 Feb 2026 in “Ask HN: Do you still physical calculators?” “I learned Calculus despite having access to Mathematica, TI-89/92/CX-CAS, and WolframAlpha”
Comment from 1 Mar 2026 in “AI is making junior devs useless” “you could do a decent amount with the CAS back in the TI-89”
Comment from 1 May 2026 in “Ti-84 Evo” - Comment from 4 Aug 2026 in “LLMs reward expertise”
- Comment from 11 Nov 2025 in “The R47: A new physical RPN calculator”
- Comment from 29 Dec 2025 in “UK accounting body to halt remote exams amid AI cheating”
Lasted years through school and engineering
“Used the heck out of those calculators because I did all the math and physics prerequisites”
Comment from 2 May 2026 in “Ti-84 Evo” “TI calculators peaked with TI-89/92/v200. Functionality, low latency UX, long battery life.”
Comment from 2 May 2026 in “Ti-84 Evo” “My ti-89 titanium got me through two engineering degrees. Loved that thing.”
Comment from 2 May 2026 in “Ti-84 Evo” - Comment from 1 May 2026 in “Ti-84 Evo”
- Comment from 11 Nov 2025 in “The R47: A new physical RPN calculator”
Portable with fast, usable interface
“TI calculators peaked with TI-89/92/v200. Functionality, low latency UX, long battery life.”
Comment from 2 May 2026 in “Ti-84 Evo” “It's a handy device; more portable than a laptop, and better UI than a smartphone.”
Comment from 11 Nov 2025 in “The R47: A new physical RPN calculator”
What people warn about
Each mark is one comment
Over-reliance on built-in algebra
“I skated through Calculus 3 by just typing everything into my TI-89. Now as an adult I have no recollection of anything I did in that class.”
Comment from 22 Jan 2026 in “Brain on ChatGPT: Accumulation of Cognitive Debt When Using an AI Assistant” “the symbolic algebra engine on my ti-89 was so good that I could rely on it instead of learning the material”
Comment from 22 Mar 2026 in “Thinking Fast, Slow, and Artificial: How AI Is Reshaping Human Reasoning” “I truly regret having become dependent on it.”
Comment from 2 Sep 2026 in “Mamdani bans AI in NYC schools” Expensive; upgraded every few years
“the product itself, which is still $110 today, is a total ripoff”
Comment from 2 May 2026 in “Ti-84 Evo” “I was having to upgrade every few years.”
Comment from 2 May 2026 in “Ti-84 Evo”
Other calculators people recommend
The four most recommended other calculators, with the same counts for each, so you can compare like for like. The tick on each bar marks the 2 to 1 line the badge needs.
| Product | Recommend | Criticize | Approval | Months | Owned | Badge |
|---|---|---|---|---|---|---|
| Texas Instruments TI-84 Evo | 41 | 53 | 44% | 4 | 10 yrs7 owners | — |
| TI-89 calculatorThis page | 31 | 8 | 79% | 8 | 28 yrs4 owners | Approved |
| HP 15C | 24 | 6 | 80% | 5 | 41 yrs5 owners | Approved |
| TI-83 Plus | 21 | 8 | 72% | 6 | 30 yrs3 owners | Approved |
| HP 48G | 16 | 1 | 94% | 9 | — | Approved |
What people said
37 of the 39 comments that mention it, newest first. Each links to the original comment.
“It was really handy for checking my work and for working on components of problems.”
“I truly regret having become dependent on it.”
“I made a lot of use of the TI-89 era CAS in college.”
“we all had either TI-89 or v200”
“Fondest memories were recreating my school C++ project in TI BASIC”
“My ti-89 titanium got me through two engineering degrees. Loved that thing.”
“just absolutely acing math with my TI-89”
“I am pretty sure I could use a TI-89 Titanium in the dark even now”
“the product itself, which is still $110 today, is a total ripoff”
“I was having to upgrade every few years.”
“loaded a periodic table on it and used it on my high school chemistry exam”
“TI calculators peaked with TI-89/92/v200. Functionality, low latency UX, long battery life.”
“I was happy to avoid the TI student tax”
“it was phenomenal in helping me understand every single math class”
“Used the heck out of those calculators because I did all the math and physics prerequisites”
“The TI-89 is how I aced the AP Math exam.”
“felt like sanctioned cheating for College Board exams”
“much nostalgic respect to these amazing calculators”
“it was much much slower to type on the soft keyboard than it is to press the actual buttons”
“You will have to pry my TI-89 from my cold dead hands”
“The way you input things like division, integrals, matrix, etc. on newer calculators like the nspire is far superior than the older calculators (eg. ti-84, ti-89, etc.)”
“you could do a decent amount with the CAS back in the TI-89”
“It was utterly essential for solving problems in a reasonable amount of time.”
“I remember the CPU was slow, but the screen was decent for its time.”
“Mini is not ideal but it's fine.”
“I definitely was able to do quite a lot of Physics with my Ti-89.”
“they were good for professionals, too, not just students”
“the symbolic algebra engine on my ti-89 was so good that I could rely on it instead of learning the material”
“I learned Calculus despite having access to Mathematica, TI-89/92/CX-CAS, and WolframAlpha”
“It hits the sweet spot for me in terms of completely covering basic and advanced features I would need from a calculator.”
“how else am I going to maintain my brick breaker dominion”
“I skated through Calculus 3 by just typing everything into my TI-89. Now as an adult I have no recollection of anything I did in that class.”
“can do a lot of calculus work”
“as it is more straightforward”
“it served me well all the way through my CE undergrad”
“It's a handy device; more portable than a laptop, and better UI than a smartphone.”
“it has a CAS (Computer Algebra System)”
Counts come from 1,795,640 Hacker News comments, November 2025 to November 2026. How we count. Report a mistake.