It's around dinnertime as 15-year-old Eric Lai boots up his computer for an online tutoring session. So why is his tutor Mary Paul about to dig in to breakfast?

Sounds like one of those tricky SAT questions, but a global marketplace trend is the answer: Eric is at home in California and Mary is at an office in south India -- 12 time zones and 8,900 miles away.

Eric's parents are among a growing group in Silicon Valley attracted to one of the latest ventures in the world of "offshoring" -- overseas tutors. An increasing number of companies are seizing on cheaper labor abroad and the reach of the Internet to undercut the cost of U.S.-based tutors and take advantage of a vibrant Asian-born immigrant community passionate about its children's education. But critics of the approach say offshore tutors don't understand the subtleties of teaching American students.

With the federal government footing the bill for students who qualify for free tutoring under the No Child Left Behind Act, millions of dollars are at stake.

Paul works for Growing Stars, a tutoring company based in Fremont, Calif. In the year that she has tutored Eric -- with text messages, Internet voice technology and a computerized "white board" -- his math grades have jumped from C's to mostly A's.

When Eric told her about homecoming at his school, "She was like, 'Huh?' " he said. Despite the occasional misunderstanding, he said, "we understand each other most of the time."

His mother, Olivia Sum, said she has seen results. "It's made him more confident" academically.

Biju Mathew, a Fremont dad, started Growing Stars about three years ago after searching for a tutor for his son and finding that most U.S. tutors charge $50 to $95 an hour. Growing Stars charges $20 an hour for Indian tutors and $30 for U.S.-based tutors who teach English. About 60 percent of the 300 students they tutor are South Asian and mostly in the San Francisco Bay Area.

The company's Indian-based tutors work 40-hour weeks for $226 to $339 a month, according to a newspaper advertisement provided by the company.

Growing Stars' Web site doesn't explain that its tutors are in India, but customers are told when they call for more information, said spokeswoman Nisha Alex.

The company's tutors have master's degrees in the subjects they teach and have weekly classes on pronunciation and American culture that include reading books such as "Uncle Tom's Cabin" and "The Da Vinci Code."

Several companies provide overseas tutors for American kids and most sell subscriptions to schools, libraries and other groups. Career Launcher, based in New Delhi, has tutors working from home to teach kids in India, the Middle East and the United States. Elluminate Inc., based in Calgary, Canada, has tutors in Canada, the United States and one in the Philippines who serves mostly U.S. students.

Tutors don't require licensing and are not regulated in the United States unless a school uses federal funds to pay for the services. Some educators, however, have doubts about tutors abroad.

Olivia Martinez, a Canada College sociology professor and Sequoia Union High School District board member in Redwood City, Calif., said offshore tutors haven't been the through the U.S. education system, don't know specific state and federal requirements, and may not know as much about California and U.S. history.

"It's inevitable that people who are entrepreneurial in spirit will try and tap into the American market, but I'm sure there are plenty of American tutors at home who could do what's needed," she said.

Tutor.com -- a New York-based company that provides online tutoring to schools and libraries -- dropped India-based tutors after a trial last year, said Jennifer Kohn, the company's vice-president of marketing. Kohn said the tutors couldn't communicate as well, ranked lower in student surveys and cultural differences made teaching hard.

But Christina Lee, who hires Stanford University students and recent graduates to tutor pupils in person, said the more groups helping educate kids, the better. Although her service charges up to $95 to coach kids on the SAT, she doesn't think low-cost tutors abroad will threaten her business.

"Our service is completely different because the parents who come to us are looking not only for a tutor but also for a mentor . . . who really connects with the student," Lee said.

Paul, 24, who earned her bachelor's degree in education and a master's in math at Indian colleges, said connecting with American students over the Internet was hard at first.

She couldn't tell whether they were saying "can" or "can't" -- since the British English word, "cannot," is easier to differentiate. She avoids using American football and baseball to teach math because she still doesn't get the rules.

But she and Eric have hit it off over their year working together. "How are you?" she asks Eric -- a phrase she was instructed to use every time she starts a session. She sometimes even uses the more colloquial, "What's up?"

Paul wears a flowing yellow and green salwar kameez, and Eric wears jeans, T-shirt and a half-dozen charity bracelets. Both wear headsets, using voice-over-Internet-protocal technology to talk, and scribble problems and solutions with a computer pen on a "white board," a blank page on the computer screen that both see. At the bottom of the screen, a text-messaging bar lets them share equations. During this session, they ponder: FLplusLA equals ATplusLA.

"Why is that true?" Paul asks Eric through his headphones.

"The additive property," he says.

"OK, what does that mean?"

After a long pause, she draws arrows to each "LA."

"Because you can add an equal amount to both sides of an equation?" he asks.

"Right!" Paul says, marking the problem with a check.

Sixth-grader Anna Nidhiry of San Jose also uses Growing Stars and plans to give up group tutoring lessons because she is moving faster than others in the group.

Anna, 10, who paints landscapes and reads mystery novels in her free time, said she had trouble with science before her tutor, Kumar Menon, came along. She said he helped her understand the intricacies of rock formations and the nervous and cardiovascular systems. If they have time at the end of a session, he'll share fun science facts, such as which creature never sleeps?

"Ants!" she said, grinning as new adult teeth flashed in a still-small jaw. "Weird, huh? They're working all the time."

Anna said she has grown to tolerate science thanks to Menon.

"I don't love it," she said, "but I don't hate it either."