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Topic: Is there a way to area model negative numbers?
Replies: 2   Last Post: Feb 3, 2005 2:37 AM

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Kevin Karplus

Posts: 190
Registered: 12/6/04
Re: Is there a way to area model negative numbers?
Posted: Feb 2, 2005 11:12 PM
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In article <akn2011gi1jk6srfquve2g9l2psjg2477f@4ax.com>, Scott Bryce wrote:
> If this is not the correct forum for this, please let me know.
>
> I am building a math worksheet generator. I am currently working on
> worksheets to practice comparing fractions. I want to provide an option
> to show area models of the two fractions. I also want to provide an
> option to include problems with negative numbers.
>
> Area models are easy. If the student is comparing 1/4 to 1/3, I can draw
> two same-size rectangles side by side. One is divided into 1/4s with 1/4
> shaded. The other is divided into 1/3s with 1/3 shaded. The student can
> see that the 1/3 shaded area is larger than the 1/4 shaded area.
>
> Is there a similar way to model the comparison when both fractions are
> negative? I could use the same models to show that 1/3 is more negative
> than 1/4, but I don't think that is intuitive.
>
> Number lines are an option. What other options are there?


Color coding (blue for +, red for -)

Above/below a zero line.
Left/right of a zero line.

Adding constant (comparing 1+ -1/3 with 1+ -1/4).

Football yardage (gains and losses)



------------------------------------------------------------
Kevin Karplus karplus@soe.ucsc.edu http://www.soe.ucsc.edu/~karplus
Professor of Biomolecular Engineering, University of California, Santa Cruz
Undergraduate and Graduate Director, Bioinformatics
(Senior member, IEEE) (Board of Directors, ISCB)
life member (LAB, Adventure Cycling, American Youth Hostels)
Effective Cycling Instructor #218-ck (lapsed)
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