Picturing names, numbers, animals, and simple concepts. Books that teach

AS nursery toys become computerized and more and more baby clothes appear with designer labels, even the world of children's literature is teaching simple concepts with a new level of sophistication. Yuppie children are being inundated with artistic, elaborate, and cleverly designed picture books. Demi is an author-illustrator who teaches with flair and innovation in Opposites (Grosset & Dunlap, New York, $10.95, 45 pp., ages 3 to 6). Her animals prance and dance across double-page spreads, dressed in texture and tapestry. Blended tones and vibrant colors mat her delicate line drawings, creating dimension and interest in her artwork.

Inside/outside, curly/straight, upside down/right side up. Identification of opposites is the theme of this newest in a series of Demi animal-game books. Demi doesn't limit her lesson to contrasting words but challenges kids to examine number, shape, color, and size in her clever designs. Creating creatures within creatures, Demi plays ``hide-and-seek'' in her compositions. In characteristic style, she combines a number of unusual techniques that are highly effective in both teaching and entertaining young children.

Tana Hoban has also enjoyed increasing popularity as a contributor to early childhood education. Challenging her readers to look more closely at the world around them, Hoban focuses on Dots, Spots, Speckles, and Stripes (Greenwillow Books, New York, $11.75, 30 pp., ages 3 to 6), her newest title. This photo book provides fun-browsing material, having captured freckled faces, flapping dresses, sleeping kittens, and feather masks.

Here is an imaginative book of pictures without text, relying on composition, color, and pattern to attract young readers. Hoban's photographs have brought her recognition internationally, and her children's books are in school libraries around the world.

BERT KITCHEN brings an interesting new approach to beginner books. Big black numbers covered with crawling, sprawling creatures teach the counting of animals in Animal Numbers (Dial Books, New York, $11.95, 22 pp., ages 5 to 8). And the emphasis is on ``animal.'' The reader is not just counting numbers, but also counting animals and their offspring. Kitchen's illustrations are detailed and anatomically correct, if not cute and cuddly. In fact, his choice of certain animals is so unusual that this book may be more helpful in a second-grade science lesson, rather than in a kindergarten counting class.

The already popular world of bears welcomes yet another addition in Bears in Pairs, by Niki Yektai, illustrated by Diane deGroat (Bradbury Press, New York, $13.95, 32 pp., ages 3 to 6). Tumbling, frolicking, walking, and crawling, a cast of costumed characters are on their way to a special gathering. Each guest is a bear, and two bears are a pair. As a result, ``Bears in Pairs'' is a wonderful rhyming picture book for young children.

NIKI YEKTAI and Diane deGroat have done a masterly job of creating some marvelous new personalities. Keeping the language simple and the descriptions brief, the creators focus on detailed, fun-filled illustrations. The colorful, imaginative characters all assemble at a tea party, the finale of the story. Mary, playing host to this gala affair on her bedroom rug, is surrounded with the full array of comical, but lovable guest bears.

In Lucy and Tom's 1.2.3. (by Shirley Hughes; Viking Kestrel, New York, $10.95, 32 pp., ages 4 to 6), the tea party is a more formal ``dining room table'' occasion, as it's a celebration for Lucy and Tom's granny. The whole family spends a busy Saturday preparing for this special afternoon tea.

As the title suggests, this is a counting book, but one in which counting happens incidentally as part of the story. Starting with early morning breakfast spoons and finishing with the candles on the cake, Lucy and Tom count their way through the day.

Children in England are very familiar with tea parties, and also with Lucy and Tom, because Shirley Hughes has written a series of books about the everyday activities of this British sister and brother. Providing lots of interesting little details in her drawings and text, these family sharing books should win approval and praise beyond the borders of Britain.

The rhyming prose and muted illustrations of The Midnight Farm, by Reeve Lindbergh, illustrated by Susan Jeffers (Dial Books, $13.95, 28 pp., ages 4 to 7), reflect a genuine sensitivity to and understanding of children's thoughts. As the night sky darkens and the world is shadowed in grays and blues, most little sleepyheads are snug in their cozy warm beds. But not so in this imaginative book as a small boy explores the barnyard at night with a trusted companion - his mother.

Offering a welcome contrast to typical nighttime tales of ghosts and goblins, this picture book presents the evening hours as a time of warmth and quiet sharing. To still her son's fears about the darkness outside his window, this perceptive mother takes him out for a walk in the summer air. They walk right into the blackness and find a world alive with the activity of familiar friends. They also meet creatures seldom seen in daylight hours: a deer visiting the orchard pond, mice scampering on the old stone wall, and barnyard geese awaiting the arrival of the wild geese.

The late-night adventure reverses the hesitation and fear often associated with darkness and midnight, and the tone of the story is echoed on the last page as the little wanderer is sound asleep in his bed, with his newly discovered world all around him:

Here is the dark of the midnight

farm, Safe and still and full and warm, Deep in the dark and free from

harm In the dark of the midnight farm.

Joan Sherman Hunt is a children's librarian and reading teacher.