- 5 - 2 = - 7
The number that you need to add to - 5 to get - 7 is - 2
This can be ssen on the number line. If you are adding, you move towards the right but since we are adding a negative number, the - sign makes the plus sign to become - sign. So we would subtract by moving 2 points to the left of -5 and that gives - 7