Teaching Math without Rules: Addition of Positive and Negative Numbers

I’ve discovered many ways of teaching math through the years and the most interesting one was the addition of numbers with opposite signs. I learned this from a teacher who said that he never understood the rules – so he made up his own method.

He “breaks” the bigger number into two pieces so it can be cancelled. Here it is:

What do you think? Can you teach it this way? Share your thoughts in the comments.