Atmosphere: Pleasant and formal.

Prices-Pasta $4.50 to $5.95: entrees $5.50 to $9.75.

Credit cards: American Express, Visa/Bank Americard, Diners Club.

Reservations: Available, necessary on weekends.

Hours: 11:30 a.m. to 11 p.m. Closed Sunday.

Special facilities: parking lot. Accessible to the handicapped. High chairs available.

The Marco Polo has a secret formula that should keep it in business for a long time - they know how to get a 5-year-old to eat and eat and eat . . . even his salad.

They're not revealing their secret, but part of it is a menu with a variety of well-prepared Italian and American dishes that also keeps the adults happy. Another part of the formula is a pleasant, quiet atmosphere in a large room, which will seat 300 but is partitioned into alcoves to make it seem like a small, around-the-corner hideaway.

The decor and the waiters' dress suits give it a formal atmosphere that is pleasant for Mom and Dad and provides a setting for the youngsters to try out their company manners. The staff is friendly and adept at dealing with children. Our waiter, after filling our water glasses, filled our baby's small bottle with great aplomb and nary a drop spilled.

We arrived early on a recent weekday, the 5:30 dinner hour being most suitable for our young children. There was no problem with seating and, we learned later, reservations are necessary only on weekends.

Breadsticks and fresh French bread kept us occupied until our antipasto was served. For $4 for two ($2.25 for one), it included enough prosciutto ham, cheese and salami, tuna, hot peppers and olives to satisfy us and to provide nibblers for our 5-year-old son.

The salad, with a mild Caesar dressing, was served next. It rated high on my salad index and miraculously passed my son's finicky palate.

My husband ordered the veal parmigiana, which he pronounced good. Our 18-month-old baby, who shared the dish and who is still without molars, stuffed it down at a rate that labeled it tender. The baby also liked my fettucine alburro, $5.25, a very good rendition of a favorite of mine. THe portions were more than adequate, and I did a double-take when I saw the child's portion of lasagna, $2.50 or half the adult price, that my son had ordered. It filled the plate, and I was even more surprised when he nearly finished it.

The restaurant has no children's menu, but the pasta and entrees come at half price for children at dinner.

Adult prices for the pasta range from $4.50 for spaghetti al ragu to $5.95 for linguine with mussels or clams in bianco.

The Marco Polo has a nice selection of veal dishes from the parmigiana to veal scaloppine Siciliana and escalopes de veau la Francaise at $7.25 and veal cordon Bleu at $7.50. It also has a variety of seafoods, including zuppa dipesce, a mixture of seafoods with linguine for $7.95. There are also chicken and beef entrees.

The wine list leans toward the Itlian but includes French and Californian selections. A liter of the imported house wine is $5.50.

We started with a cocktail, passed up the wine and were too full for dessert. Our bill came to $26.80, including tax and tip.