It's no news that U.S. students are falling behind other nations in math skills. Two recent studies confirmed a trend that businesses have noticed for a while. Now some company owners are responding to the challenge, picking up a responsibility that used to belong exclusively to the public school system.

Here are the numbers we're working with: In an international study sponsored by the Paris-based Organisation for Economic Co-operation and Development, 15-year-old American students performed below average among all 40 participating nations and ranked beneath most industrialized countries on math (they did tie with Latvia). Another test, the Trends in International Mathematics and Science Study, placed U.S. fourth-graders 12th of 25 countries in math and eighth-graders 15th of 45 countries.

Unless the trend is reversed, economists worry that businesses will struggle to find employees who have mastered basic math skills. Moreover, companies will find themselves spending more and more time and money on training programs to get workers up to snuff. Carhartt, the outdoor-clothes manufacturer, realized that employees at its Hanson, Ky., facility had a hard time using some equipment because they had weak math and computer skills, so the company parked a mobile classroom at the plant and held classes after shifts ended. Similarly, Manda Fine Meats in Baton Rouge, La., offers biweekly tutoring sessions in its boardroom.

Both of these firms were able to get help from local government agencies as well as nonprofits, which are springing up around the country. Some focus on literacy training, others seek to improve local schools. In San Bernardino, Calif., for example, business leaders and local educators have joined forces to start the Alliance for Education, which asks companies what skills they need from high school grads and brings businesspeople into classrooms to pose real-life business questions to students. "It's in everyone's interest to increase the pool of qualified workers," says real estate developer Randall W. Lewis, one of the group's founders.