Students will then explore the different situations that come up. This works well with students working in pairs. You can give them a worksheet with sample problems or allow them to come up with their own to test. Remind them to test a variety of cases. This process will help students understand what really occurs with integer operations on a deeper level. They will also remember the rules better when they have worked to develop them on their own.
You will need to start by discussing zero pairs. Get out some kind of manipulative that can represent positive and negative numbers.
Another option is to use manipulatives in two colors - any little counting teddy bears or even cut up paper squares will work!
I like to have my classes write rules in "If ___, then ___" format. Give your students the structure you prefer, and then let them get busy!
As students work, they can use this two-page worksheet to guide them. They will develop their own rules for integer addition and subtraction.
I have included two versions, so you have options for differentiating or for different levels of guidance. If you and your class are not yet comfortable with inquiry-based learning, try the more structured version.
Click on the image of the worksheet to download.