Archive for December, 2009

A Rant on Calculators

December 27, 2009

Normally, I talk about religious issues here. My role as a former math teacher is just screaming at me today, however. I was blessed to receive an HP 50g graphing calculator from my in-laws for Christmas. To my mind, it is the best calculator currently on the market! After having a little time to get to know it over the past two days, I’m am more convinced of that than ever.

So, what’s the rant about? The silly TI monopoly that exists in the public schools, and even in some colleges. Students are pushed to buy the “latest and greatest” TI calculator. When I was teaching, it was the TI-83 or TI-84. The funny thing is, all the students seemed to use them for was playing games and avoiding learning how to graph. The effect is that parents are paying over $100 for a calculator that will be confiscated as a gaming device (which it’s not that good at).

My frustration is two-fold. First, while TI does make nice calculators, there are equally effective teaching tools available for far, far less money. Casio has an excellent, easy-to-use, graphing calculator for only $50. Sure, the interface is different from those on the TI’s, but as a calculator it is every bit as effective and useful. Add the more limited programming abilities, and you have a calculator that is less likely to have video games loaded on it.

If you think that $50 is a lot of money, and I know many people do, there is another option. Go to Big Lots! They have a programmable, graphing calculator for $16! True, it has lower resolution than the Casio or TI calculators, but has a small manual and just works.

Financially, then, I view TI calculators as a burden on parents of students. Public schools push these very over-priced devices on students, with the threat of not helping a student with the calculator if it isn’t one of the proscribed devices.

Educationally, there is an even larger problem. No teacher seems to be able to give a coherent reason as to WHY the students need these. The standard answer I received was “They need it for the ACT” or “They need it for the SAT” or something similar. It was the most amazing thing, however. When I went to the sites for those tests, they clearly stated that graphing calculators were generally allowed, but not required. Certain graphing calculators (the TI-92 being the only one I know of that meets their ban criteria) aren’t allowed, and none are required.

What happens, then, is that graphing calculators make certain topics easier to “teach”. Graphing is a great example of this. Which is harder, to teach a student how to correctly graph y=x^3, or teaching them how to enter it into the calculator and let the calculator do it? The answer is obvious. Graphing calculators can automate many processes. How many students don’t know the quadratic formula because their calculator could do it for them, or be programmed to do it for them?

Unfortunately, at colleges, graphing calculators are not greeted with the same, warm enthusiasm they are in high schools. A graphing calculator can store every physical constant and formula quite easily. The physics and chemistry teachers know this, and frequently ban them from tests. Why? Because it’s like carrying a cheat sheet in with you.

By contrast, the math departments will tend to snicker at you if you bring in a graphing calculator. Why? Because it won’t do you any good in most classes! Outside of algebra, calculus, and differential equations, classes tend to be 90% theory and 10% calculation, at best. Some have essentially no calculation at all, or so much that a computer and programming experience is required.

The impact of all this is that high schools teach students to rely on calculators that will be banned in college. Without their calculators, these same students suddenly find themselves crippled as the holes in their math education are exposed.

Do I enjoy my new fancy calculator? Absolutely. With that said, I have picked up a few graphing calculators over the years. Two came from my wife when we got married, one was a present,one was a cheap toy (the $16 Big Lots calculator), and one is the HP 48GX I’ve had for over a decade. I had a TI 81 when it came out. I used its graphing features about twice in calculus. I used my brain daily.

Make students learn the math. Only after that, should they be allowed to use the calculator.