Sign:  When you add two integers, keep the sign of the number with the largest absolute value.

For example, (-2) + (1)

Start at -2 on number line and move one unit to the right. You will get -1. So (-2)+(1) = -1. As we can see the sign of the answer
is negative.

What if both integers have same sign ? 

For example: 2+5,

Rule still applies! You can still keep the sign of the number with the largest absolute value, that is positive sign of 5.
So you can start at number 2 on line and move 5 units on right. You will get 7.
So 2+5 = 7

Another example, (-2)+(-5)

Again, rule still applies! Start at -2 on number line and move 5 units on left. You have to move to the left as sign for 5 is negative.
You will get -7.

What if both integers have different sign ? 

We already did one example above.

One more example, 2 - 5 = 2 + (-5)

Start at number 2 on number line and move 5 units left on the line. Again you have to move to the left because sign of 5 is negative.
You will get -3. As we can see the sign of answer is negative because largest number is -5 and it's sign is negative.

                  ADDITION TABLE

                  PRACTICE ADDITION AND SUBTRACTION