Back to Unit 7

Rules for Adding Integers

If the integers have the same sign, add the numbers and keep their sign:

     example:  +4 + +3 = + 7    {adding two positive numbers - answer is positive}

                     -4 + -3 = - 7      {adding two negative numbers - answer is negative}

 

If the integers have different signs, subtract the numbers - keep the sign of the larger absolute value.

     example:  -3 + +10 = + 7    (10-3 = 7 and so the answer is positive

                    + 3 + -10 = -7  (10 - 3 = 7 and so the answer is negative

 

Same signs - add 

Different signs - subtract