Which Graphing Calculator to Buy?

From students, students' parents, other teachers, former students, and even my parents on occasion comes the question asked of every math teacher since the days of the slide rule: "What calculator should I buy?" The trouble with what seems to be such a simple question is that the answer is certainly not simple. Here is my best attempt at it though and I hope this will help those of you out there currently plodding to Staples with a big question mark in a bubble over your head. Please keep in mind that this advice is almost exclusively for a high school or middle school aged student - undergraduates should talk to their professors to understand exactly what is expected of them.

Before I get to my specific recommendations, let me throw out some general wisdom:

You probably don't need to buy one

That's right, you don't need one. No - this isn't coming from some old curmudgeon who insists that every student do arithmetic by hand lest his fingers get rapped - rather, it is important to understand that your math teacher more than likely has a calculator that you can use during class time. Bringing your own calculator to school exposes you to the liability of losing it, having it stolen, or broken. Further, you may find that your teacher is less willing to help you with "technical" difficulties if you bring in a calculator that is significantly different that the class-set of calculators available in that class. 

I bought a TI-89 my sophomore year in high school for my Pre-Cal class and it was stolen less than a month after I had it. That was a very, very sad day for me - but I have not bought a calculator since. Yes, it is nice to have your own, but you really don't need one. 

You might not be allowed to use it anyway

In just about every single upper-level engineering course that I took at Texas A&M I was not allowed to use a calculator during the tests. At home studying we almost always used online tools like Wolfram Alpha or even simplier, Microsoft Excel, to do all the math we needed. 

Many high schools prohibit the use of personal calculators on standardized testing as well, so your fancy $100 toy that you've been studying with for the last several months turns into a brick that you can't use - I'd rather not be put in that situation.

HP 32sII - Just Awesome

You don't need the best, or newest

The funny thing about calculators - not much has changed in the last several years. We're not talking about the mobile phone race here kiddos - the software behind plotting y=2x+2 has remained relatively unchanged since I was in high school. That means you can go on Craigslist, buy a 10-year-old calculator, and be just as equipped as the next guy. Another funny thing about calculators is that they last for a really long time. One of the few things that routinely dies on a calculator is the battery - which can be replaced!

An "old" TI-82 does most of what the latest-and-greatest TI-eighty-something can do but can be found used for probably less than $10 without looking too hard. 

You might not even need a graphing calculator

Since that TI-89 was stolen from me back in high school, I've been using my trusty HP-32sII RPN scientific calculator just about every day (and have replaced the batteries maybe once in ten years). Unfortunately, HP stopped making the 32sII but eventually replaced it with the 33s, and then the 35s. Any of these scientific calculators is more than an adequate tool and (once you get the hang of them) may actually be more handy than any graphing calculator. 

HP 35s Scientific Cal.

Interestingly, the 32sII can only be found at exorbitant prices because it is just such a novel find. A used 32sII in decent condition is easily several times the price of a brand-new 35s.

So after much ado, here is my list of calculators you should think about buying.

1. Hewlett Packard 35s Scientific Calculator

The HP-35s is a more than capable scientific calculator which can be had for about $40 and does everything you'll ever need a hand-held calculator to do.

2. TI-Craigslist

If you really must have your hands on a TI-something-or-rather (which, quite frankly, are all very nice machines) I strongly recommend doing a craigslist search for "TI-82" or "TI-83". If you can find either for about $10 go ahead and buy it. Honestly, there is no sense in wasting ten-times that amount on a TI-89 that provides marginally more utility. 

3. Microsoft Excel (or similar)

My last recommendation is not a hand-held calculator at all - please do all of your future engineering professors and employers a favor and learn how to manipulate numbers in a spreadsheet function. Your graphing calculators skills become almost useless after high school, but your spreadsheet skills will become more and more relied upon. Please, please, please learn Excel. Please. Thank you. 

So that's that - I supposed if I could answer our title question more succinctly it would be : "well you don't need a graphing calculator at all!"