Certain concepts in math are necessary for critical thinking. Many people, however, struggle to learn these concepts well thereby reducing the effectiveness of their policy choices.
In a country of over $12 trillion dollars deficit (and counting), about 80% of people cannot concieve of the magnitude of a trillion. Very small quantities are equally confusing, because people are unaccustomed to seeing them in their everyday lives. However, thanks to wonderful videos and interactive comparisons you can get a better sense of how orders of magnitude work.
Of course, that's only a very small part of overall numeracy. Probability and statistics, it can be argued, play an important role in everyday discourse, especially as we continue to be bombarded by facts and figures of every sort. When I was younger, someone told me a joke:
Two boys are walking home from school and one asks the other, "What's the chance that I'll see a man riding a dinosaur in the street?"
His friend thinks for a moment, and responds, "Fifty percent. Either you will or you won't."
At the time I recall laughing very hard. As I got older, this joke became less funny for I encountered more and more people who surprised me with their ignorance and actually maintain variations of this sort of thinking.
I currently do not have any solutions to this problem, yet I do not believe it unsolvable. Part of the issue may lie with trying to solve the wrong problem. But that will have to be another post.