# Can anyone share knowledge on TI-84 calculators?

#### Alpha6

##### New member
I am a tutor (Math and Science) and was looking to purchase a new calculator.

The TI-84 plus costs about $109 new and the TI-84 Plus (color) costs$130 new.
I am wondering if purchasing the color one is necessary, and if it has any features that makes the price difference worth it. On the cover of the package it says good for Biology, Chemistry, and Physics as well! How does it help in these subjects, has anyone used either of these before?

#### ksdhart2

##### Senior Member
I've had both calculators, and I honestly can't recommend spending extra for the color one. The main change made to the TI-84+ is that it can make graphs in color (Gee, really? Who'da thunk it? ). This can sometimes be useful if you're trying to compare multiple graphs on the same plot, as trying to do so in black and white is hard. The regular TI-84 will draw multiple graphs in different patterns, but I find them very difficult to distinguish.

Aside from that, I only noticed two other changes: The color version has a bigger screen and uses its own rechargeable batteries, whereas the regular TI-84 uses two AA's. I did enjoy the bigger screen, but I just don't think it's worth the extra \$21. And unless you plan on using your calculator for a very long time such that the expense of buying batteries would add up, I don't see how that could be worth it either. When I was heavily using my calculator for math classes, I recharged the battery on my TI-84+ about once every two months, and I changed the batteries in my regular TI-84 about every three months.

However, TI does make two other types of calculators that might be worth splurging for, though I've not personally used either one and I don't know how much they cost. The TI-89 Titanium and the TI-Nspire CX both have computer algebra systems, meaning they can compute and calculate symbolic representations, such as telling you that $$\displaystyle \displaystyle \int x^2 \: dx = \frac{1}{3}x^3 + C$$ rather than only being able to compute definite integrals like the TI-84/+ can. Here's some links to information pages about these calculators, from TI's website.

#### Harry_the_cat

##### Senior Member
Just be aware that it is often the case that CAS calculators cannot be used in formal exams

#### Otis

##### Senior Member
Alpha6 is a tutor.

#### Harry_the_cat

##### Senior Member
Alpha6 is a tutor.

Yes I saw that. But he still needs to use a similar calculator to the one his/her students use.

#### Otis

##### Senior Member
Yes I saw that. But he still needs to use a similar calculator to the one his/her students use.
I think that's why he's considering buying one! The students' materials probably refer to the calculator, regularly.

Or, is your warning about exams intended for him to pass on to his students?

#### Harry_the_cat

##### Senior Member
I'm talking about the computer algebraic system (CAS) calculators. If they are banned in student's exams, then the student needs to make sure they can work without one. The tutor (or teacher, or student for that matter) may well use CAS calculators as a teaching/learning aid but needs to be familiar with the calculators the students are allowed to use in an exam situation. In other words, students shouldn't rely on their calculator to do algebra for them. (I suppose I am following on from post #2 from kdshart2.)

#### Otis

##### Senior Member
… I am following on from post #2 from kdshart2.
Oh! You didn't quote kdshart2, so I had thought you were talking to the OP, heh. My goof (I "suppose").

Sorry Otis.