Often integers (positive and negative numbers) are difficult to add and subtract. Here's a hint. Use money, temperature, or a number line to help know what direction you are going. Negative signs mean go down, go back,or you owe money. Subtraction signs mean do the opposite of the sign in front of the second number. Example: 3 - 4--- means go up 3 then go the opposite of up 4 (which means down). So you land on -1.
Example: -6 - (-8) ---- means go down 6, then go the opposite if down 8 or up 8 and you land on 2.
Example: 5 + (-9) ---means go up 5, then go the down 9 to land on - 4
Example: -2 + (-3) ---means go down 2, then go down 3 more and land on -7