Great for remediating and introducing! I enjoyed doing this foldable with my 8th graders. Not only did I give them the rules, but I also gave examples to show why the rules work. The feedback that I got from my students was great, as many of them said that it helped them with integers and it made operations alot easier.
I didn't include an answer key because your rules may not be like mine; but if needed, I will provide one.