Silvia Koch asks some of the 27 children in her combined second and third-grade class at Arlington's Key Elementary School, "What is on my hand?"

"That is a rubber band," they answer. Then, one after another, the children put the rubber band on their hands, repeat the question and get the same answer.

The exercise may seem a simple one, but Koch's pupils speak little or no English. In fact, collectively they speak 14 languages, from Spanish, Arabic, Nepali, Afghani and Laotian to various Chinese and Indian dialects. The rubber-band exercise helps them learn not only words, but also how to form sentences and ask questions that will help them learn other words.

Koch's class is a special one that meets all day for intensive language training, but its cultural diversity is representative of the school at large. As of Dec. 1, 40 percent of Key's 475 pupils in kindergarten through sixth grades have limited proficiency in English and get special language training during the school day, according to principal Paul Wireman. The students come from 33 countries and speak 17 different languages.

Key School, in turn, reflects the growing enrollment of foreign-born and minority students in the Arlington school system.

In 10 of the county's 33 schools, including eight elementary schools, white students now are in the minority, according to a recent county study. The numbers of both black and white students have been declining the last few years, while the numbers of foreign-born pupils, particularly Indochinese and Hispanics, have been rising.

The biggest change has occurred in the grade schools. At Key this year, for example, school statistics show Asians account for nearly 18 percent of the enrollment; blacks, 7 percent; whites, 39 percent; and Hispanics, 36 percent.

Those numbers alone cannot reflect the full story of Key's ethnic composition because they do not differentiate between the native-born, English-speaking pupils and the foreign-born children who speak little or no English. A student of Hispanic descent, for example, may be native born and speak English while a black child may have come from Sierra Leone and speak Temre, or a white student may be from Portugal and speak Portuguese.

When the school scheduled parent-teacher conferences last fall, it had to bring in Vietnamese, Chinese, Spanish and Korean interpreters, said Marsha Dale, a teacher who also coordinates Key's complex English instruction program. Some messages sent home to parents also carry bilingual translations, she said. And when a Vietnamese parent walks in unexpectedly, Wireman may call on the Vietnamese-speaking janitor to help out with translation, since none of the teachers speaks Vietnamese.

"You feel forever like you're working in a little United Nations," added Judith Jacoby, school librarian.

Key's multicultural composition, Wireman said, "requires the school to really work to meet all levels of need for all of its students." He emphasized that while the school has a large concentration of non-English speakers, it does not cater exclusively to the foreign born. "We are here to work for and with all the students," he said.

Both Wireman and the teachers say the difficulties sometimes inherent in a multicultural, multi-lingual school are more than offset by the benefits: the opportunities to learn of other countries, languages, foods, holidays, religions and leaders.

Key runs a panoply of programs designed to hasten the adjustment of non-English speakers. "The ultimate aim for all of these (foreign-born) students is to give them enough proficiency in English to successfully function in the classroom," said Dale. "As soon as they've done that, we exit them" from the program.

Before entering the school, foreign-born students are screened at the county's Intake Center. They are then placed in programs and classes appropriate to their knowledge of English. If they are not put into a special all-day class for English-deficient students, however, language proficiency has no bearing on homeroom class placement, a school spokesman said.

Programs at Key for those with little or no English proficiency include:

* ESOL (English for Speakers of Other Languages): For those in kindergarten through third grade, as well as 5-year-old preschool Montessori pupils. Students spend 30 to 45 minutes daily in ESOL classes, being drilled in English and given supplementary help in understanding concepts discussed in regular classroom lessons. They spend the rest of the day in regular classes.

Dale describes ESOL as a "pull-out program" requiring less intensity than some other programs. "The younger you are, the quicker you're going to pick up the language," she said. "It's easier to pick up concepts taught at this level because academic content isn't as heavy in the earlier grades, so children learn more quickly."

Key has 145 students in ESOL classes.

* HILT (High Intensity Language Training): For those in grades 4 through 6, with beginning and intermediate/advanced sections. These are all-morning sessions in listening, speaking, reading and writing. Students also get help in understanding regular classroom lessons. They return to regular classes in the afternoon for math, science and social-science lessons.

Key also has a special, all-day HILT class of second and third graders, taught by Silvia Koch.

At Key there are 44 students in HILT classes.

* Transitional Classes: All-day classes for Spanish-speaking students where concepts -- such as addition in mathematics -- are reinforced in Spanish for pupils who know virtually no English. The lessons are taught in English, but occasionally the teacher uses Spanish to communicate better. Transitional class teachers are bilingual, but the school does not require additional language proficiency of its other teachers, Wireman said. These students attend no other classes.

* LADO: Classes in reading readiness for Spanish-speaking kindergarteners. Teachers help students learn things such as the alphabet and key words in Spanish, so they can understand the English counterparts. The program is named for its creator, Dr. Robert Lado, linguistics professor at Georgetown University.

Key teachers acknowledge that the students' shuffling in and out of classes -- and particularly in and out of the school, which has a high transiency rate -- can be frustrating.

"We have them coming and going continuously, that's for sure," said Mamie Spellman, a kindergarten teacher. "It means you have to bridge the gap for those coming in and hope they will fit in with those that are here.

"It can disrupt the program if a group is beginning to read (words) and you get someone who hasn't started reading letters. Then there's always one at a different level, and you have to spend extra time helping that child catch up with the others. . . . (But) that's where the ESOL program really helps out. It reinforces what we do (in class)."

If an English-deficient student has trouble understanding something in a social studies lesson during a regular class, the student will get special help on that point during the next ESOL class, for example, school officials explained. As a result, they said, there is close coordination between regular-class teachers and those who teach the special language sessions.

But John Carmichael, who teaches a group of 27 fourth- and fifth-graders, including 16 in the HILT program, denies that English-speaking children get less attention. Motivation, he says, is the key: "Some students who are not highly motivated tend to slack off, but it's not due to the HILT students at all."

The teachers also point out that students at other schools also go in and out of classes for special help in reading, speech therapy and other such classes. Besides the language classes, Key has special classes for students with learning disabilities and classes for academically gifted students as well.

"This is a fun school to work at," said Key second-grade teacher Kitty McQueen. "But it's also the hardest school to teach at in the county, because there are so many different ethnic groups that blend together. But their cultures have enriched our school and all of us."

The effort at Key to help the foreign students learn English has been complicated by another factor, according to principal Wireman: the high transiency rate of Key students. In the last school year, he said, more than 250 new students enrolled or re-enrolled after prolonged absences, and another 88 withdrew during the year.

Condominium conversions of low-rent apartment buildings within the school's district and tighter restrictions on the number of persons who can legally occupy a dwelling in some nearby buildings have contributed to the high transiency rate, parents and educators agree. Many of Key's foreign students live in those buildings, which are being snatched up by developers in anticipation of massive redevelopment around the Courthouse Metro stop.

The transiency rate and the large number of students who do not speak English spurred many Key parents last month to protest the proposed merger of two other nearby grade schools, Taylor and Woodmont, where -- in contrast to Key -- native-born, English-speaking pupils are a vast majority.

The school board is scheduled to vote on that proposal tonight.

The Key parents want to get back two areas of single-family housing, some within three blocks of the school, that were taken out of Key's district in the past 10 years. And they would like other such neighborhoods in the Woodmont district to be transferred to Key's district if the merger is approved.

Single-family residential areas are crucial to a stable school population base, the parents maintain. Some Key parents told the school board last month they believe the highly transient, non-English-speaking population at the school is straining the school's academic program. The faculty, which the parents described as very dedicated, is forced to spend extra time helping the newcomers catch up, they contended.

Wireman said the Key staff is remaining neutral in the controversy, but does endorse the return of the two neighborhoods lost in redistricting.

"The parent community we have here -- those who have been here for some time -- seems to be very supportive of the school, very proud of it, and accepts some of the very positive benefits their children get from being in a multicultural setting," Wireman said.

"I have been asked by people if Key is experiencing 'white flight,' " he said, "but I haven't really seen it, not anything I can put my finger on." In fact, Wireman added, he gets more requests for children to be transferred to Key than for them to be taken out of the school.