• To add two integers with the same sign, add their absolute values and keep the same sign.
     
     
    To add two integers with different signs, subtract their absolute values and keep the sign of the number with the larger absolute value.
     
     
    To subtract an integer, add its opposite.
     
     
    The product or quotient of two integers with the same sign is always positive.
     
     
    The product or quotient of two integers with different signs is always negative.