Could improving students' math skills boost financial literacy? Some policymakers think so.
New data show American teens' money smarts are, at best, middling. 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. Worse, 17.8 percent of the 15-year-olds tested didn't meet proficiency standards—meaning they're unable to apply basic concepts such as value for money.
"The sobering news here is that we're average," U.S. Secretary of Education Arne Duncan told attendees at a Global Financial Literacy Excellence Center event in Washington, D.C., on Wednesday to release the data. "We're at the middle of the pack."
Data from the OECD study shows a correlation between students' math skills and their performance in financial literacy, said Andreas Schleicher, director of education at OECD. In most countries, students who performed well at math had even higher financial literacy scores.
In some cases, it's clear that it's the math, and not exposure to personal finance. Shanghai-China, for example, topped the personal finance assessment despite not exposing students to dedicated coursework in the subject. "All the teaching and learning in Shanghai focuses on conceptual understanding," Schleicher said.
With that in mind, we have a steep slope ahead. In the OECD's math performance test, the U.S. was classified as "below average," with a dismal rank of 36 out of 65 countries. Of U.S. students who took that test, 25.8 percent failed to meet basic proficiency.
"We're not going to improve our financial literacy rates until we start doing better at math," Duncan said.
Some possibilities are already in place. Standardized tests could work in more math questions with a practical personal finance application, Richard Cordray, director of the Consumer Financial Protection Bureau, told seminar attendees. Math textbooks used to, and could once again, incorporate both household and broader economics. "We need to regain that common-sense focus," he said.
Bigger changes are also in progress. Forty states have raised standards on math and other subjects, Duncan said. The aim? "More current, more rigorous, more complex thinking skills," he said. "Less mile-wide-inch-deep." Such changes, he expects, could start to make an impact when the math and personal finance tests are next administered in 2015.
He pointed to Tennessee, which adopted Common Core standards in 2010. There, the percentage of fourth-grade students tested as proficient in math rose to 40 percent in 2013, from 28 percent in 2009, according to the National Center for Education Statistics' 2013 Mathematics Assessment Report Card.
It's a start, he said. "We have an opportunity in the next couple years that we as a nation, frankly, haven't had in a couple decades," Duncan said.
—By CNBC's Kelli B. Grant