Interesting article... sort of.
The problem is that the questions aren't financial questions, they're basic math questions. So, does it become harder when you use terms like inflation, or do we just suck at math?
I do remember that, when I was going through my 7th grade work, we used a finance book as the math book that year (I was home-schooled). My mom showed it to a finance major at college who stated that she never went through anything like that in high school and was just now covering the same material I was. I wish some of that had stuck!