A Math Forum Project

Learning to Mentor
Replying Example 1

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Replying to Students || Next Example
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From: Student 4, age 15
To: GeoPOW Staff
Subject: GeoPOW: Congruent Rectangles

Answer:

the perimeter is 114 square units

Explanation:

used X and Y as sides of one of the smaller rectangles. X is the
longer side.

4y=3x  x=4/3y
7xy=756
7 4/3yy=756
3/4x4/3yy=108x3/4
324/4=81
yy=81
y=9
4x9=3x 36=3x
36/3=12
12=x
5x+6y
60+54=114 square units

From: Student 4
 

[The student looked at answer 1]

From: Student 4
 

Actual written comment:
i showed all my work and found the right answer

   
Problem Solving Notes
interpretation       He has completely solved the problem.
strategy       It looks like he chose a good strategy and executed it well.
accuracy       Everything looks accurate.
Communication  
completeness       He wrote it all down, but didn't say where any of it came from.
clarity       He hasn't explained anything so that another student would understand if they don't already.
reflective       Doesn't reflect at all.
From: [the mentor]
To: Student 4
Date: Sep 9 2002 10:47AM
Subject: Re: GeoPOW: Congruent Rectangles - posted 09/02/02
 

>the perimeter is 114 square units

Hi, [Student 4].  Your answer is right, as you saw, and you did show all of your
work.  But what you didn't do was _explain_ your work.  That's another important
step in the process.

So while you've chosen a good strategy and you've got the math all correct,
you also need to explain what you did.  You should describe the steps that you
took and do it in such a way that another student would be able to learn from
reading your work.  Also, once you're finished, try to reflect on your work -
can you check your work (besides using our answer check)?  Does your answer
seem reasonable to you?   You can read more about what this part might look
like on the page that is referenced below.

See what you can do with this.  I look forward to seeing your revision.

    -[the mentor]


>
>used X and Y as sides of one of the smaller rectangles. X is the
>longer side.
>
>4y=3x  x=4/3y
>7xy=756
>7 4/3yy=756
>3/4x4/3yy=108x3/4
>324/4=81
>yy=81
>y=9
>4x9=3x 36=3x
>36/3=12
>12=x
>5x+6y
>60+54=114 square units

--

Summary:

        Problem Solving Interpretation: Practitioner
            Problem-Solving - Strategy: Practitioner
              Problem Solving Accuracy: Practitioner
            Communication Completeness: Apprentice
                 Communication Clarity: Novice
              Communication Reflection: Novice
          
(For an explanation of scores see http://mathforum.org/pow/scoring.html.)

--
[the mentor], for the Geometry Problem of the Week
http://mathforum.org/geopow/

Next Example

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Annie, annie@mathforum.org
December 2002