Pre-Algebra Review Topic
Adding Signed Numbers
Topic Index | Algebra Index | Regents Exam Prep Center

 

Rules for Adding:
  When you add two numbers with the same signs,
    1.   add the absolute values, and
2.   write the sum (the answer) with the sign of the numbers.
 
  When you add two numbers with different signs,
    1.   subtract the absolute values, and
2.   write the difference (the answer) with the sign of the number
      having the larger absolute value.

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Examples:    Add :
 
1.  -9 + (-7) = -16

 

5.   6 + (-2) = 4
2.   –20 + 15 = -5

 

6.   (-21) + 21 = 0
3.   (-23) + (-7) = -30

 

7.   –3 + 8 = 5
4.   (+3) + (+5) = 8

 

8.   -9 + 6 = -3

9.  Add -9 and -5.  Answer:   -14

 

10.  Add (-7), (+3), and (-12).  Answer:  -16