On the chalkboard was a math problem written in kanji, or Japanese script. The teacher, Chisa Shimamura, looked around the room for a volunteer to solve it.

"That's easy," a boy exclaimed.

Easy, maybe, for the third-graders in Room 112 of Great Falls Elementary School in northern Fairfax County. Unfathomable, probably, for most of their peers, parents and even their principal.

While politicians in Washington decry America's inability to compete with Japanese industry, Great Falls Elementary is trying to do something about it. More than 90 first-, second- and third-graders at the school spend half of each school day learning in Japanese as part of a language program that is among the first of its kind in the nation.

"Ninety percent of Japanese businessmen speak English and 10 percent of our businessmen speak Japanese," Principal Gina Ross likes to point out. "When I say that figure, I don't think we need to say much more."

Language immersion programs such as the one at Great Falls, in which students spend part or all of their days speaking and learning in a foreign tongue, have become increasingly popular across the Washington area and the country in recent years. However, nearly all are in European languages.

Aside from Great Falls and two other Fairfax elementary schools -- Floris and Fox Mill in Herndon -- the only schools in the United States focusing on Japanese are in Fairbanks, Alaska, and Eugene, Ore.

The three experimental Fairfax programs, launched a year ago with a $276,000 federal grant, have attracted growing attention from educators and politicians alike. Rep. Frank R. Wolf (R-Va.), who helped win the federal seed money for the program, and U.S. Education Secretary Lauro F. Cavazos toured the Great Falls school yesterday in an effort to highlight the program.

Students at Great Falls have a two-part day: during one part, they study English and social studies in English. During the other, they learn math, science and health while speaking in Japanese.

Shimamura never speaks English. If students don't understand, she repeats her words, miming her meaning.

When a boy fails to comprehend that she's asked him to sit down, she extends her hands, palms down, and gestures downward until he understands. Then she repeats the command for reinforcement.

Before lunch yesterday, Shimamura ran her third-graders through a math lesson in which they matched numerals with their respective Japanese kanji.

After a student finished, the others clapped and said, "Hai," if the answer was correct.

Shimamura worries that not all of her students understand.

"Sometimes I'm very frustrated because some children are very good, go faster," said Shimamura, who was born in Japan and moved to the United States in 1973. "Some children still don't listen so well, get behind. The gap is getting bigger."

That worries some parents as well. Rachel Rissetto, whose 8-year-old daughter, Elizabeth, is in her second year in the program, said she thinks the complex Japanese characters may be too difficult for children.

"We would've liked it better if it were a language we were used to hearing, like Spanish or French," she said.

Students agreed that reading and writing kanji are the toughest parts.

"You've got to do them exactly right, because if you do it even just a squiggle off it's an entirely different letter," said Erika Starr, 9.

Many parents said they are excited that their sons and daughters are learning a language that will put them on the cutting edge academically. "It can be nothing but an asset," said Nancy Nelson, mother of third-grader Ryan, 8.

"If we get to learn a second language, maybe one of us would become the . . . ambassador" to Japan, said Brandon Long, 8.

Some students see a potential value in Japanese as a code, incomprehensible to most adults.

"I can't wait to go to my mom and cuss anytime I want," said Paul Monica, 8, who so far has not learned any bad words.

Ross, the principal, freely admits that the students have left her far behind. "I have no idea what they're saying," she said. "I just assume it's good and smile."

The students have mastered one phrase out of necessity: Otearai ni itte ii desuka? It translates: "May I go to the bathroom?"

If they get it wrong, the answer is no.