Two negative numbers are added, and the sum is negative, and then their absolute values are added (the absolute value is the difference between this number and 0, for example, the absolute value of 3 is 3-0=3,

The absolute value of -3 is 0-3 = 3), the sum of two positive numbers is positive, and then the absolute values are added. Such as -3+-2=-(3+2)=-5.

Positive plus negative, take the sign of the number with large absolute value, and then subtract the small absolute value from the large absolute value, such as -3+5=+(5-3)=+2.

-6+2=-(6-2)=-4