[nfbcs] FW: Scientific Calculator

Thu Jun 28 00:17:44 UTC 2012

I think Leah is saying that on her TI 84 calculator if there's no operator between a number and a grouping, her TI 84 calculator assumes the missing operator is multiplication; but, Angie's calculator does not make this assumption.

So  5 (3 + 2) would equal 25.  NOTE: read the equation character by character if you're using a screen reader.

I question Leah's statement that her TI 84's behavior is the "normal" or "correct" behavior.  However, she is the teacher, and it is her class.

I guess my suggestions fall along the lines of teaching Angie how to use the calculator she has correctly, learning how to use an RPN calculator where parens are not necessary, finding an accessible TI calculator program for her computer (unlikely I think), or working with a reader to use the calculator her classmates are using.

Does this help get things started?

Jim

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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