American teens may know the mall like the back of their hand, but their knowledge of financial topics such as saving, spending and investing is average at best. The first large-scale international study on financial literacy among 15-year-olds came out on Wednesday, and the results are grim. Among the 18 countries in the Organization for Economic Cooperation and Development's assessment, the U.S. ranked at best eighth and at worst 12th, based on the range of scores from its 1,133 students tested. Globally, more than 29,000 students took the test. "How do you feel when you get the 'also participated' ribbon?" said Ted Beck, president and chief executive for the National Endowment for Financial Education, in an interview with CNBC. "That's kind of where we are." U.S. teens scored a mean 492 on the OECD test, eight points below the overall global mean of 500—and more than 100 points below first-ranked Shanghai-China's 603. A small bright spot: Girls had mean scores of just one point lower than boys, much less of a discrepancy than in other countries. Want to take the test yourself? Click here.
-- By CNBC.com reporter Kelli B. Grant