So are you asking how you add a positive number to a negative number? If so, think about a number line. If you have a negative number, you are to the left of zero. To add a positive number, you will move to the right. You will move by the number of spaces that the positive number tells you to. You will end up with a bigger number than you started with. It might still be negative, it might be positive, or it might be zero.
- -4 + 3 = -1 -- you get a bigger number (to the right on a number line) but it's less than zero.
- -4 +4 = 0
- -4 + 5 = 1
Forget about the sign, for the beginning and think as the numbers would be both positive. Then subtract the smaller number from the larger.
The answer will then receive the sign of the larger number.
we'll have to add 2 and -4.
We'll pretend that both are positive.
Now, we'll subtract the smaller number from the larger one.
We'll subtract 2 from 4.
4 - 2 = 2
Now, the answer will receive the sign of the larger number. The larger number is 4 (the absolute value of 4) and it has minus sign, so the answer will receive the minus sign.
-4 + 2 = -2