Calculator Flaw Forces Recall in Virginia

Jivecat writes "CNN is reporting that TI is recalling 11,000 calculators issued to students in Virginia because of a flaw that would give them an unfair advantage on standardized tests. A 12-year-old discovered that by pressing two keys at once, the calculators will convert decimals to fractions. The tests require the students to know how to do this with pencil-and-paper." So the calculator is being recalled because it's not crippled enough. Maybe it's a good time to question the wisdom of issuing expensive electronics to students in the first place, though I'm sure the calculator companies would rather you didn't.

Uh, isn't it TI

[captainbeardo]

Am I blind or does it say Texas Instruments, not HP?

i dont get it...

[zxnos]

...if they have to do know how to do it by hand, why do they even have a calculator available during the test. back in the olden days (90's) we had to take an exam w/o calculators to prove compentency before we could use them in class.

Re:And I suppose they will give them back!?

[e9th]

The photo seems to show that the replacement models hace a different color faceplate, so I guess one motivation might be that if you're caught using an old one on a test, you are toast.

Re:And I suppose they will give them back!?

[crazyvas]

The motivation is this: Virgina allows only "state-approved" calculators to be used in standardized tests. If you don't send your calculator back and receive the fixed one, you won't be allowed to take your test with the old calculator. http://www.pen.k12.va.us/VDOE/Assessment/Calculato rUseonSOLTests.pdf [k12.va.us]

Re:Off-Topic(?): Decimal to Fraction Algorithm?

[HermanAB]

Here is a PDF paper: http://tinyurl.com/cfgl4 [tinyurl.com]

School calculators

[Emerssso]

I'm a Chesterfield native, and am familiar with these calculators, since I know kids who use them. Those particular calcs are only issued for SOLs (the local flavor of standardized test) and when a student forgets to bring his/her own. The point is to be dumbed down to four function & square roots so that you don't get to use higher functions on the Big Test, but other than that, you can use whatever you want. Since one of the goals is to make you do things like conversion on paper/in your head, that is purposefully excluded. (The point is not to see if a Middle Schooler can add, hopefully they wouldn't have gotten this far without that particular ability.) So, yes, even though this seems very silly (as do the tests) there is a reason why this is a problem.

Heh, the Casios always fly in under the radar....

[otis wildflower]

.. Especially the ones without large LCD graphing displays. My trusty beast [rskey.org] could handle at least first year chem and physics formulae.. And you didn't have the TAs refusing or confiscating them like they might some of the more advanced (and waay more expensive) HPs.. And no RPN ;)

Plus, you could get them at Service Merchandise (and possibly Consumers Distributing), which were the only places my folks bought consumer electronics back in the day...

(and for all you hatas out there, Casio _did_ have a more powerful [rskey.org] programmable, but IIRC it was also way more expensive at the time..)

Re:log books

[jmarans]

I'm posting a comment because your thread took on a teaching bent, and I've just finished a BEd. I taught grade 11 math during my last practicum and discovered that the calculator generation doesn't think about math the way the pre-calculator generation does. We, the latter, have a set of learned computational tools that have been supplanted by electronics.

I set a test and cooked the numbers so the students wouldn't need calculators, and their stress levels went nonlinear at the thought.

I talked with someone who teaches at a private school in Australia and was told calculus students normally learn to do derivates on their calculators now, no one teaches the differentiation rules down under any longer.

I wonder if it matters to any but a very small few.

Re:A flaw?

[marcansoft]

Actually it seems to me like the engineers figured out "aha, we'll just remove the key" and not realize that (due to the way the keyboard is wired up and the way the software scans it) it is possible to make it think you pressed other keys. I figure they wanted to save themselves the hassle of changing the controller chip design, or they were just lazy or too stupid.

1 2
| |
A-B-3
| |
C-D-4
| |

Take a keyscanning algorith that works scanning left-to-right columns and up-to-down rows, that decodes the first key detected as pressed and ignores the rest. Take a keyboard matrix as shown above, with no isolation diodes. Press keys B,C,D. Watch how the connections 3-2,2-4,4-1 also create a 3-1 connection. Now the calculator just thought you pressed A. Depending on the details of it, similar stuff can happen. For example, if the thing worked by switching inputs and outputs e.g. sending current to all columns and watching for the active row, then sending current to all rows and watching to the active column, two keys (B and C) would be enough to activate all the rows and columns in the previous matrix. The calculator checks the first it finds and voila, it happily performs the funcion assigned to "A".

Re:It's not really about the math.

[mysidia]

Setting the bar as low as you suggest begs the question: Why teach anything that you can use a calculator for?

He's not begging the question. Begging the question is a rhetorical tactic that involves use of an essentially circular argument, making a proof reliant on itself, but, he's only stated an opinion.

The fact of the matter is conversion of non-repeating decimals to fractions is simple enough, and this is fundamental to the understanding of fractions, a rudimentary mathematical skill that any person learned at elementary level or better should be adept at, just like every reasonably educated person should know what the Constitution is, know a little history, plus some of the general basic ideas in literature, reading, writing, biology, and the physical sciences..

We are not talking rocket science or even things so advanced as trig here, kids should learn this. It does not matter if they will need to use this particular item from mathematics often in their work, but they might later find the skill was very useful to have.

There are a lot of skills kids should learn. Some of them will be useful in their lives, some of them they might not be useful. But there is no way to tell for sure in advance, and certainly they won't be useful if never acquired (probably it means they lost some benefit or satisfaction they would have had if they had learned the skill).

If educators in Virginia have found that their students tend to have difficulty converting decimals to fractions (or otherwise dealing with fractions), then they surely should be testing them on the related skills.

There are more important and fundamental topics, yes, but the notion of fractions and the understanding of how to get them how to work with them, etc, are far from unimportant.