From: Jackie <shorty21258@aol.com>
To: Teacher2Teacher Service
Date: May 31, 2001 at 10:06:45
Subject: Subtracting integers

My son is in the 6th grade and he is learning to subtract intergers. He is 
getting confused when the problem is +11 - +12 = +1. Both numbers are positive 
so does he just subtract or does he change the sign of the second number, then 
change the minus to plus and follow the rules for addition? 
So the problem then becomes +11 + -12 = -1? Here is one of his problems. 
-10 - -7 = -3 is his answer. Now both the signs are negative and he just 
subtracted, are you suppose to change the minus to a plus and change the 
 -7 to a +7 and then follow the addition rule? So that problem becomes 
 -10 + +7 = -3. He got the same answer so why would you change anything? 
 So why wouldn't +11 - +12 = +1?  

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