Math Problem into a story book?

We were given an assignment to take a math problem and create a storybook of that problem. It's suppose to be creative. Our math problem is 3-(-2)=5. How am I suppose to create a story for children that explains WHY it equals 5. Obviously, I know how to do the problem. But creating a story is hard. We were given examples of simple addition problems incorporated into a story, but our problem is harder because it's not just a simple 3+2=5. It's a matter of somehow creatively explaining why 3-(-2)=5. Thank you for your help! :)