I had a store across the street from a local high school. At lunch, we got some kids in to make a purchase or two. 90% had no clue what tax was, how to figure it out, or what their change might be if they purchased a $5 item at 8% tax.

Regularly they would hand me a $5 bill and then argue that no tax was due. When they did learn about tax, they couldn't tell me how much it added to their cost, it was..........really sad.