# TI-89 calculator Hacker Approved page: https://hackerapproved.com/p/ti-89-calculator/ 25 people recommended TI-89 calculator in Hacker News comments, 6 had mixed feelings and 8 criticized it, November 2025 to October 2026. It was recommended in 8 of 12 months, in 9 threads. It meets the Hacker Approved badge rule. **Verdict:** 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. Summary written by Claude from 37 comments. ## Why people recommend it - Helped with exams and homework (6 comments in the sample): "It was really handy for checking my work and for working on components of problems." ([source](https://news.ycombinator.com/item?id=50047807)) "It was utterly essential for solving problems in a reasonable amount of time." ([source](https://news.ycombinator.com/item?id=47856063)) "loaded a periodic table on it and used it on my high school chemistry exam" ([source](https://news.ycombinator.com/item?id=47983356)) - Covers basic and advanced math (6 comments in the sample): "It hits the sweet spot for me in terms of completely covering basic and advanced features I would need from a calculator." ([source](https://news.ycombinator.com/item?id=46876935)) "I learned Calculus despite having access to Mathematica, TI-89/92/CX-CAS, and WolframAlpha" ([source](https://news.ycombinator.com/item?id=47212009)) "you could do a decent amount with the CAS back in the TI-89" ([source](https://news.ycombinator.com/item?id=47980114)) - Lasted years through school and engineering (5 comments in the sample): "Used the heck out of those calculators because I did all the math and physics prerequisites" ([source](https://news.ycombinator.com/item?id=47983090)) "TI calculators peaked with TI-89/92/v200. Functionality, low latency UX, long battery life." ([source](https://news.ycombinator.com/item?id=47983329)) "My ti-89 titanium got me through two engineering degrees. Loved that thing." ([source](https://news.ycombinator.com/item?id=47991512)) - Portable with fast, usable interface (1 comment in the sample): "It's a handy device; more portable than a laptop, and better UI than a smartphone." ([source](https://news.ycombinator.com/item?id=45891881)) ## What people warn about - Over-reliance on built-in algebra (2 comments in the sample): "the symbolic algebra engine on my ti-89 was so good that I could rely on it instead of learning the material" ([source](https://news.ycombinator.com/item?id=47474544)) "I truly regret having become dependent on it." ([source](https://news.ycombinator.com/item?id=49543725)) - Expensive; upgraded every few years (2 comments in the sample): "the product itself, which is still $110 today, is a total ripoff" ([source](https://news.ycombinator.com/item?id=47983595)) "I was having to upgrade every few years." ([source](https://news.ycombinator.com/item?id=47983434)) ## Other calculators people recommend - [Texas Instruments TI-84 Evo](https://hackerapproved.com/p/ti-84-evo/): 29 recommend, 10 mixed, 50 criticize - [HP 15C](https://hackerapproved.com/p/hp-15c-calculator/): 21 recommend, 2 mixed, 2 criticize - [TI-83 Plus](https://hackerapproved.com/p/ti-83-calculator/): 15 recommend, 4 mixed, 8 criticize - [HP 48G](https://hackerapproved.com/p/hp-48g-calculator/): 13 recommend, 3 mixed, 1 criticize ## Where to get it - [Official site](https://education.ti.com/en/products/calculators/graphing-calculators/ti-89-titanium) - [See price on Amazon](https://www.amazon.com/s?k=Texas+Instruments+TI-89+Titanium+graphing+calculator) ## The badge A product earns the Hacker Approved badge when at least 10 people recommend it, recommenders outnumber critics at least 2 to 1 (mixed feelings count toward neither side), it was recommended in at least 4 of the 12 months and in at least 5 different threads, and no single thread supplies more than half of the people who recommend it. Health and money products are never badged. ## Cite as Hacker Approved, "TI-89 calculator", https://hackerapproved.com/p/ti-89-calculator/ (25 recommend, 6 mixed, 8 criticize; Hacker News comments, November 2025 to October 2026). Counts updated 2 Nov 2026, with data through October 31, 2026.