[nfbcs] FW: Scientific Calculator

Doug Lee dgl at dlee.org
Wed Jun 27 23:51:18 UTC 2012 

Parentheses in algebra are used as grouping yes, but it is also legal
to write two expression terms together with no intervening
multiplication symbol. Thus, (x+2)(x-1) is correctly interpreted as
"the quantity x plus 2 times the quantity x minus 1."

I don't know what modern scientific calculators allow in regards to
leaving out multiplication symbols. My first question, though, is
whether this is a calculator that has been modified beyond just adding
speech. The message thread here implies that the calculator itself is
misinterpreting input and actually leaving out the first term in the
given example. (I would add, parenthetically for the humor of saying
so, that although things like (x+2)(x-1) are extremely common in
algebra, I'm not so sure things like 3(x-1) are so common without the
multiplication dot.)

If this calculator is just a run-of-the-mill TI calculator but with
added speech support, the issue is that the student did not understand
the calculator's input rules accurately. Whether the calculator's
input rules are good ones is probably a separate discussion. In other
words, if the TI calculator can be bought in a store without speech
and does the same odd thing, this is not about exceptions or
accessibility.

But if the speech modifications to this calculator actually changed
the way the calculator interprets input, or if the calculator is
custom in the first place to the point that its actual math logic is
not standard for a TI device, then we have a very real problem and the
student has, in my opinion, every right to complain to the makers of
the calculator and to ask for special handling of past mistakes caused
by the device.

That's how I see this, anyway.

On Wed, Jun 27, 2012 at 04:30:09PM -0700, Humberto Avila wrote:
Based on my recent knowledge of Algebra, I definitely agree with Mike. Parentheses are not multiplication but are used to separate numbers and follow order of operations. And no, computer calculators do not interpret parentheses as multiplications either. I have tried simple calculations before, and it just treats the parentheses, when being used instead of the multiply (*) sign, as just numbers and leaves the first number entered out and gives the second number as the result.

The issue with what this scientific calculator is doing may mean a couple of things:
A.  either the calculator is interpreting the parentheses when used as grouping symbols wrong, or
B.  the student is inputting the information wrong on the calculator, or
C.  there may be confusion between the student and / or the DSS coordinator with the instructor regarding calculating solutions to the problems with the material being covered in class.

I might be wrong, but this is what I know of this so far.


-----Original Message-----
From: nfbcs-bounces at nfbnet.org [mailto:nfbcs-bounces at nfbnet.org] On Behalf Of Mike Freeman
Sent: Wednesday, June 27, 2012 4:15 PM
To: NFB in Computer Science Mailing List
Subject: Re: [nfbcs] FW: Scientific Calculator

Parentheses aren't multiplication; they're grouping symbols. 

Mike Freeman
sent from my iPhone


On Jun 27, 2012, at 16:02, "David W Bundy" <bundy at pobox.com> wrote:

> 
> 
> I wonder if any of you have any suggestions re the below situation.  She is using the Orion TI35.  (I have removed names from the original e-mail to preserve confidentiality)
> 
> From: ****Sent: Tuesday, June 26, 2012 5:09 PM
> Subject: FW: Scientific Calculator
> 
> 
> 
> 
> 
> I need to inform you that ****???s math instructor, ****, has made a disturbing discovery.  ****???s talking scientific calculator does not compute correctly (see email below).  I have a different brand of talking scientific calculator in my office, and unfortunately, it has the same limitation.  This is completely unfair and unfortunate for ****.
> 
> 
> 
> The error in computing caused ****to get many of her homework and test problems wrong, even though she may have entered the information into the calculator correctly (in the format that is taught and is standardly used).  We would like to correct this problem as soon as possible.
> 
> 
> 
> I am requesting that you investigate other calculator options that would work for **** in an educational setting; this would be one that reads parentheses as multiplication.  
> 
> 
> 
> I would be glad to discuss this further if you would like.
> 
> 
> 
> Thank you for your attention to this!
> 
> 
> 
> 
> 
> 
> Sally Herlong, M.Ed.
> 
> Department Manager
> 
> Special Resources/Disability Services
> 
> York Technical College
> 
> 452 S. Anderson Rd., Rock Hill, SC 29730
> 
> Tel: 803.325.2896 | Fax: 803.325.2897
> 
> 
> 
> 
> 
> 
> 
> The information transmitted via this email is intended only for the addressee and may contain confidential and/or privileged material. Any interception, review, retransmission, dissemination, or taking of any action upon this information by persons or entities other than the intended is strictly prohibited. If you receive this communication in error, please contact us at 803.981.7111, and delete the communication from any computer or network system.
> 
> 
> 
> 
> 
> From: Leah Hollingsworth 
> Sent: Tuesday, June 26, 2012 10:52 AM
> To: Sally Herlong
> Subject: Scientific Calculator
> 
> 
> 
> Sally, 
> 
> 
> 
> As we discussed, Angie???s scientific calculator is not reading parentheses as multiplication. For a basic compounding interest problem, I would enter in ???12000(1+.09)^7??? into my TI 84. (See the screen shot below.)
> 
> 
> 
> Screenshot of correct processing of a scientific calculator. It reads: 12000 (1+.09) raised to the 7th power = 21,936.46945.
> 
> TI 84 calculator screenshot 1
> 
> However, when I entered it into Angie???s calculator, using the same notation of ???12000(1+.09)^7???, my answer was 1.828039121,which is (1+.09)^7. It is not reading the parentheses as multiplication. I then attempted the problem again, however pressing Enter twice, to see if that would take into account the multiplication of 12000 out front and it didn???t. The answer it gave me was 68.21790833, which is 1.828039121 raised to the 7th power. 
> 
> 
> 
> I asked two colleagues whether they thought a ???scientific??? calculator should be reading parentheses as multiplication and they both agreed. Even basic calculators are able to read parentheses as multiplication. 
> 
> 
> 
> Please let me know if you need any more information from me or if I can do anything else to help.
> 
> 
> 
> Thanks
> 
> Leah
> 
> 
> 
> 
> Leah Hollingsworth
> 
> Instructor
> 
> Mathematics
> 
> York Technical College
> 
> 452 S. Anderson Rd., Rock Hill, SC 29730
> 
> Tel: 803.981.7720 | Fax: 803.981.7216
> 
> 
> 
> 
> 
> 
> 
> The information transmitted via this email is intended only for the addressee and may contain confidential and/or privileged material. Any interception, review, retransmission, dissemination, or taking of any action upon this information by persons or entities other than the intended is strictly prohibited. If you receive this communication in error, please contact us at 803.981.7111, and delete the communication from any computer or network system.
> 
> 
> 
> 
> 
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-- 
Doug Lee                 dgl at dlee.org                http://www.dlee.org
SSB BART Group           doug.lee at ssbbartgroup.com   http://www.ssbbartgroup.com
Reality is not what we see.  Reality is what is, whether we see it or not.
(03/01/09)

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