Together with literacy, loyalty and Lenin, there is a fourth L in the Soviet school lexicon -- labor.

From first grade on, children in the Russian national school system take at least two classes a week of trud, labor. The aim is to give youngsters, even children heading for solely intellectual professional careers, training in such practical skills as sewing, carpentry, cooking, metalworking, typing and household repair.

This is quite fitting in the workers' state, but self-sufficiency in homemaking and home repair can be more than a question of ideological tenets or saving on repair bills. In the Soviet Union, women who want the latest fashions frequently must sew their new clothing themselves, since the state-run design shops are noted chiefly for frumpy styles. The owner of the family car cannot depend on the local garage to handle repairs -- spare parts are scarce and repair stations even scarcer.

It is also appropriate in a nation where seemingly every important street corner caries a huge slogan urging greater productivity for the party from the people of Lenin that grades for trud count. A failing mark of two can pull down the overall average, just as the top grade, a five, can raise it.

IN MOSCOW SPECIAL School No. 5, which our three children attend, trud in the first three grades might better be called arts and crafts. The 7-year-olds worked with clay in the fall term, then moved to nature collages of leaves and nuts gathered on class outings. But, led by their teacher, Lyudmila Mikhailovna, Chandler and his classmates soon moved into the world of practicality: they learned rudimentary sewing stitches and now are fashioning arithmetic answering cards for numbers drills.

Second-grade children sewed napkins and bookmarks, practiced wrapping packages and created wall decorations for their parents' flats.

By third grade, boys and girls together practice sewing, making for themselves the red armbands they must wear when it is their turn to clean the classroom after school. Some will wear similar red armbands as adults, working as volunteer police auxilaries during rush hour, on state festival days and at major spectator events. They are called druzhiniki, or bodyguards, and can detain citizens for police arrest. As in the United States, some consider this service an honor.

At the formal start of the "middle school" in fourth grade, the 10-year olds are divided by sex and attend separate trud classrooms to be taught by specialists. In our school, the boys take up carpentry and metal work and the girls begin serious sewing and some cooking.

BRENNAN'S SHOP has two rooms equipped with power lathes and drills, plus a wide assortment of hand tools. His teacher, Yuri Maximovich, 50, is very popular, in part because he is one of only four male teachers in the school of about 750 pupils, and also because he exudes sturdy self-confidence. "There's nothing you can't do if you work at it," is his axiom, the kind of manly reassurance any kid among us could respond to. He also teaches drawing and draftmanship and has the kind of easy precision that inspires emulaton.

So far, under Yuri Maximovich's careful direction, Brennan has made a tin box, a small tin shovel which he wrapped and presented to his mother as a birthday present, and a hinge.

NINA'S CLASS has concentrated on sewing under the watchful and demanding eye of Dina Davidovna, a plump older woman with a very direct approach -- "That's no good!" I'll divide a two and give you each half!" -- that has earned her the wary respect of her classes down through the years.

Their homemaking room includes an assortment of foot-powered treadle sewing machines, hand-crank machines, and some electric-powered models which the girls so far have not used. They have concentrated on mastering the intricacies of the foot-powered models, practicing their stiches on paper without thread first to get the hang of it. The current project is to make white cotton aprons and kerchiefs to wear to trud. Right now it is slow going, with Dina Davidovna taking them carefully through the tedious steps of measuring, transferring sizes to paper patterns, pinning and cutting out cloth, and basting them together before they go through the machine itself.

Earlier in the year, the girls worked at a long table in the center of the room, making decorative tea sandwiches such as your grandmother used to serve at lawn parties. Nina's experiment of making them in the shapes of crocodiles and piglets was promptly sequelched with the firm opinion that squares and triangles would be just fine, thank you.

She got fives anyway.