Q&A #6501

Context stories to explain negative numbers

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From: Claudia (for Teacher2Teacher Service)
Date: Jun 13, 2001 at 15:27:43
Subject: Re: Context stories to explain negative numbers

Here are a couple of ideas........
I have something I created for work with integers. I use copier 
and make a master of smiley and frowny faces. When you explain to the 
that a positive and a negative make a zero it is hard for some to VISUALIZE 
it. But when the smile is placed on the frown, they form a 0 zero! For lack 
drawing here to give you an idea the positive looks like
          + +         and the negative   - -
         smile                          frown

For example   -2 + -4 = ?
          Have the students place two frownie faces in their work
space. Then since ADD means to add pieces to the work space, they place 4
more frownie faces.  How many faces in all?   6  but they are all negative so
-2 + -4 = -6

Example:   -2 + 4 = ?
           Begin again with the two frownie faces, add 4 smiley faces.
What happens to 1 frownie and 1 smiley, they are placed on top of each other
to become a zero....this happens to the other +, - pair...so the workspace
has two zeros, and +2 (two smiley faces) left....so the answer is +2.

*********  There is also a story to tell about the Good Guys (+) and the Bad
Guys (-). Coming to town is good for the town so that = +. Leaving town is
bad = -.

When the Good Guys (+) come to town (+) the town is very happy ...so (+)(+)=
When the Good Guys (+) leave town (-) the town is sad  (+)(-) = (-)
When the Bad Guys (-) come to town (+) the town is sad  (-)(+) = (-)
When the Bad Guys (-) leave town (-) the town is happy   (-)(-) = (+)

 -Claudia, for the T2T service

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