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Accentuate the Positive - Eliminate the Negative

Have you ever wondered why a negative number times a negative number equals a positive number?  As my mathphobic daughter would say, "No, Mom.  Math is something I never think about!"  Well, for all of us who tend to be left brained people, the question can be answered by using a pattern.  (Have you noticed a reoccurring theme in my articles?  All Math is Based on Patterns!


Let's examine 4 x -2 which means four sets of -2.  Using the number line above, start at zero and move left by twos - four times. Voila!  The answer is -8.  Locate -8 on the number line above.  Now try 3 x -2.  Again, begin at zero on the number line, but this time move left by twos - three times. Ta-dah!  We arrive at -6.  Therefore, 3 x -2 = -6.

Here is what the mathematical sequence looks like.  Moving down the sequence, observe that the farthest left hand column decreases by one each time, while the -2 remains constant. Simultaneously, the right hand answer column increases by 2 each time.  Therefore, based on this mathematical pattern, we can conclude that a negative times a negative equals a positive!!!!


Isn't mathematics amazing?



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