[nfbcs] FW: Scientific Calculator

[Mike Freeman]

I contend that the calculator needs operators explicitly entered and doesn't recognize paper notation although parentheses are interpreted as grouping signs. 

Mike Freeman
sent from my iPhone


On Jun 27, 2012, at 16:51, Doug Lee <dgl at dlee.org> wrote:

> 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.