What can you do with this* sign?

Wrap your brain around this one. Makes perfect sense. Doesn't it? I just checked on my calculator and the total is right. Even in Gold Hill over a 150 years ago they would have gotten an "A" for addition. But making sense out of things wasn't one of their strong points.

This sign - well actually one similar to this - gave me an idea for what I (or you) can do with this.

Here is what I did with it in a 6th grade math class. (Click here.)
* See #WCYDWT on twitter.