They're barely out of diapers and already learning the building blocks of reading and math. In Junior Kumon, an educational program started in Japan, children start tutoring as young as age 2.
The program is becoming popular in the United States too. Sabrina, 3, started the program last year, and her 4-year-old sister, Savi, is enrolled as well.
"She's already a step ahead," said the girls' mother, Tanuja Rathi. "You know, going in before even kindergarten and being able to read is tremendous."
Parents pay about $100 a month for two 15-minute lessons a week, reinforced with daily homework.
The program for the youngest children officially started last summer. There are already more than 7,000 students enrolled at 300 U.S. locations.
Kumon, the company that runs the program, says the market for tutoring toddlers is exploding, as families have fewer children and more money to spend.
But critics of this approach say the drills and the timed assignments are "too much too soon."
"Many families think that education is a race and that somehow if I prepare more, faster, better, my child will come out ahead," said Barbara Willer of the National Association for the Education of Young Children.
Most educators believe toddlers learn best at play. Tutoring, some say, can even be harmful if the pressure turns a child against classroom learning.
But Kumon insists their students gain an academic advantage.
"There isn't pressure to build a smarter child," said Kumon education specialist Andrea Pastorok. "Kumon wants all children to maximize their potential."
That is what Roxy Goebel is hoping for her 4-year-old son, Will.
"I think that teaches him a lifelong lesson of a great work ethic," she said.
Will isn't sure about the work, but so far, he's up for the challenge.
"It makes me kind of happy coming here," he said, "and um ... I think that's it."
ABC News' Barbara Pinto filed this report for World News Tonight.