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HP Forum Archive 18

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a very unscientific survey
Message #1 Posted by Don Shepherd on 14 Apr 2008, 2:19 p.m.

I asked my 3 8th grade math students (girls) their opinion of the 12cp 25th anniversary edition, the 17bii+ gold edition, and the 17bii+ silver edition. Here are the results.

12cp - boring

17bii+ gold - boring

17bii+ sliver - cool (as calculators go, not cool like an Ipod)

Interesting.

      
Re: a very unscientific survey
Message #2 Posted by Stephen Easterling on 14 Apr 2008, 3:13 p.m.,
in response to message #1 by Don Shepherd

Are they all making As in the class? If so, then "cool!" Otherwise, not "cool."... they need RPN to retrain their thinking.

            
Re: a very unscientific survey
Message #3 Posted by Don Shepherd on 14 Apr 2008, 3:20 p.m.,
in response to message #2 by Stephen Easterling

Actually, two of them have A's, and one currently has an F. I don't think RPN will help the one who has the F. I'm trying to teach "FOIL", and they do OK most of the time, but then I give them (x+3)2, and they say it is x2 + 9 instead of the correct answer, x2 + 6x + 9.

                  
Re: a very unscientific survey
Message #4 Posted by Stephen Easterling on 14 Apr 2008, 4:30 p.m.,
in response to message #3 by Don Shepherd

I recall there were times I was so anxious to learn math just in order to understand the buttons on my calculator! Never under estimate the power of an inspiring calculator. (At that age, kids can use all the inspiration they can get.)

                  
Re: a very unscientific survey
Message #5 Posted by Allen on 14 Apr 2008, 5:47 p.m.,
in response to message #3 by Don Shepherd

Don, while writing a 48G program to to discrete time-domain convolution , I realized that Polynomial Multiplication was the exact same process.

Perhaps if you tell them they are doing College-Level EE work, they will feel more proud. It is easier to visualize anyway when you look at the signal functions anyway instead of formulas. Reverse the second signal and then shift from the left, multiply and add. For example: 

Discrete Signals:                                |                                                        
                                                 |  
                                                 |
                                            |    |
                                            |    | 
                                            |    |
        |                  |                |    |
        |                  |                |    |
   |    |    conv.    |    |    =      |    |    |
-----------        ----------      ----------------------
   x  + 3             x  + 3           x^2+ 6x  +9
                  
Re: a very unscientific survey
Message #6 Posted by Allen on 14 Apr 2008, 6:19 p.m.,
in response to message #3 by Don Shepherd

BTW, Don, Thank you for your work training the young minds! I remember the trouble some had with "FOIL". The ones who didn't understand the concept didn't really appreciate that it was only good for binomials, and of limited utility. It is probably some requirement of the state to teach the FOIL method, more useful to show the commutative property so they could multiply and combine terms. I miss the good old days when that was the hardest things I had to do!!

                  
"FOIL": a very unscientific survey
Message #7 Posted by Karl Schneider on 14 Apr 2008, 11:44 p.m.,
in response to message #3 by Don Shepherd

Hi, Don --

Quote:
I'm trying to teach "FOIL", and they do OK most of the time, but then I give them (x+3)2, and they say it is x2 + 9 instead of the correct answer, x2 + 6x + 9.

Hmm, why might "FOIL" not be intuitive? Everyday multiplication utilizes it: 

  23
x 14                                 F       O      I     L
----   =   (20 + 3) * (10 + 4)  =  20*10 + 20*4 + 3*10 + 3*4  
 322                            =   200  +  80  +  30  +  12
                                =   322

-- KS

                        
Re: "FOIL": a very unscientific survey
Message #8 Posted by Don Shepherd on 15 Apr 2008, 7:20 a.m.,
in response to message #7 by Karl Schneider

I did use the analogy to regular multiplication when I first introduced the subject of multiplying binomials:


(x+2) x (x-1)

        x + 2
  x     x - 1
-------------
      -1x  -2
   x2 +2x
-------------
   x2 +x   -2
My students "usually" do fine in applying FOIL to side-by-side binomial pairs, like (x+3) (x-1), but they see (x+2)2, where this is no obvious "first/outer/inner/last", and they therefore just square the two terms individually. You just have to keep after them....
      
Re: a very unscientific survey
Message #9 Posted by Bruce Bergman on 14 Apr 2008, 10:40 p.m.,
in response to message #1 by Don Shepherd

I would totally agree! While I do have a fondness for the original 17bii+, with its rubberized feel (can't drop the thing), the silver is catching all sorts of attention. Even the guys in our Finance department were eyeing it the other day. ;-)

Did you show them the original 17b? Or maybe a 50g? I'd be interested in hearing what they think of those...

Cheers, bruce

            
Re: a very unscientific survey
Message #10 Posted by Don Shepherd on 15 Apr 2008, 7:24 a.m.,
in response to message #9 by Bruce Bergman

I'll show them the original 17bii and see what they think. I don't have a 50g, but I'm sure they would say "boring" to that one with all its functions. Incidentally, they are not especially fond of the TI graphing calcs either!

      
Re: a very unscientific survey
Message #11 Posted by Raymond Del Tondo on 15 Apr 2008, 12:46 a.m.,
in response to message #1 by Don Shepherd

> 17bii+ gold - boring
>
No wonder, since the '17bII+ gold' (and the '10bII') are two of the ugliest calcs they've ever made IMHO,
virtually safe from beeing stolen due to their ugliness.

Imagine how hard I had to fight with myself spending _money_ on one of each unit for my collection...

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