Nothing retiring about retirement. Senior-citizen centers, like the one in Milton, Fla., provide older Americans with hot meals -- as well as activity and companionship

MOST of the 60 or so older Americans in the hall are singing: ``Count your blessings, one by one.'' Few use hymnals; they know the verses by heart. Some of the voices are off key. But there is no shortage of enthusiasm as they belt out one hymn after another, led by an elderly pianist and several elderly singers.

This is not a church meeting. It's one of the daily events at the senior center in this rural town in the Florida panhandle. Soon, a hot lunch will be served.

But senior centers like this one offer ``much more than a hot meal,'' says Bob Cosby, coordinator of the National Institute of Senior Centers, a part of the National Council on the Aging. They also provide recreation, exercise, lectures, and, most of all, companionship and friendship.

Each day, 3 million to 4 million older Americans across the nation go to a local senior center. Of about 8,000 centers in the United States, many also offer medical assistance, physical therapy, transportation, and calls to shut-ins, Mr. Cosby says.

The centers are a way for older Americans to stay more active, get out of their homes once a day, and have fun. Many come looking for companions, someone special in their life, he says.

``A lot of people can't afford a condominium-type environment,'' Cosby says. Senior centers offer a cheaper alternative for activity and social contact, although they are open to people of all income levels.

The nutritional programs at senior centers are federally funded, too, but the number of centers is much fewer than he'd like to see, Cosby says. Meals are free, but diners are asked to make a small donation. In Milton, where many participants live on low incomes, donations range from a few pennies to an occasional $20 bill.

The seniors here, seated on metal folding chairs at long tables, drink refreshments from disposable cups. Three overhead fans help fight the heat. The crowd is integrated in an area that, like many places, at one time saw few interracial gatherings.

``It just suits me here,'' says K. Novie Strickland, 83, a former farmer from Alabama dressed in clean, blue coveralls. ``I'm happy. I have plenty to eat. I'm here among my friends; I make friends.'' A few minutes earlier he'd sliced a piece of onion and laid it beside the lunch plate of Minnie Rivenbark, who likes onion with her meals.

James Duncan, a retired carpenter, takes a seat at a table and introduces himself to a visitor. ``You'll find this is a joyous crowd, a clean crowd,'' he says. ``You ought to come to one of our senior-citizen dances. I average two dances a week.''

Senior centers can be a catalyst for older people to get out of the house, experts say. The center in Milton has helped some formerly home-bound people become active, by offering free transportation to and from the center, says Ann Spencer, executive director of the Santa Rosa County Council on Aging, which sponsors the center.

It gives the participants ``something to get up for,'' says Betty Taylor, senior- center director. ``Otherwise, they sit around in their nightgowns.''

Lizzie Jenkins, 83, has the opposite problem. She's so busy that she's supposed to be two places in one night. She sings with a local chorus and a regional chorus, and both are meeting the same evening.

Mrs. Jenkins is also a pastor's aide at her church and is active at the senior center in Milton.

``I'm into everything I can to keep me going,'' she says. ``I just love being with people. I can't, just can't sit down and do nothing.''

She claims some credit for helping break down social barriers between blacks and whites at the senior center, by encouraging people in ``loving one another.''

Mrs. Jenkins, who is separated from her husband, has just returned home from her regular weekday visit to the senior center. Today was her shopping day, and a driver from the center took her and two of her friends to and from a local mall.

The key to happy retirement is ``attitude,'' says director Spencer. People need to stay active and challenged as long as they can, she says. People retire and ``think they can fish, hunt, and play golf. You can't do that 24 hours a day.''

Indeed, the search for creative retirement -- or staying active as an older American -- is confronting more and more people. In 1982 there were almost 27 million people age 65 or older in the US. That number could rise to more than 58 million by 2025, the US Census Bureau projects.

But federal funding for senior citizens has not kept pace with inflation -- or with the growing number of retirees, says Arthur Fleming, US commissioner on aging under President Nixon.

Currently, nearly 30 percent of total federal spending is for people age 65 or older, according to the US Senate Special Committee on Aging. More than half of that is for social security. The rest is for such things as medicare, medicaid, housing, and food stamps.

The most pressing need now is for home-care services that enable older Americans to remain in their homes for as long as possible, says Daniel Quirk, executive director of the National Association of State Units on Aging. There is a ``critical'' shortage of such services, which include nursing and housecleaning, he says.

Morris Polen of Hollywood, Fla., is one who has made an individual effort to meet that shortage. Although he is 91 himself, he does most of the shopping for two neighbor women, 93 and 101.

He wheels his grocery cart out from behind the front door of his second-floor apartment, rides the elevator down to street level, and walks 12 blocks to a grocery store. He is no longer allowed to drive.

Even so, Mr. Polen hestitates when asked if he'd like someone from a local community center to give him a ride to the store. Like millions of older Americans, he wants to be as independent as possible.

He says, however, that he might like to help others by becoming a community- center volunteer. He says he likes being needed by his neighbors.

Like most older Americans, Polen lives in his own place, as opposed to a nursing home or a retirement community. And he cares for his sister, who lives with him.

About half of all Americans age 65 or older live in households with their spouses. But about a third live alone, and the percentage is increasing, according to the Census Bureau.

Mrs. Jenkins, who lives in a small two-bedroom home, gets by on $310 a month from social security and a related supplement (SSI). ``I'm happy. I don't need a whole lot,'' she says.

MINNIE Rivenbark, arriving home from the senior center in this small town, walks unaided up the path to her apartment. When she first came to the center two years ago, Mrs. Rivenbark, 93, used a walker. And she couldn't raise her arms above the level of an armrest on a chair.

Last year she was one of the featured speakers at the center's 10-year anniversary celebration, where she demonstrated the gentle aerobic exercises she had learned at the center, raising her arms straight over her head.

Now, walking past marigolds she planted near her front door, she enters her one-bedroom apartment. In her kitchen, on the pantry shelf, are jars of pears, jellies, and tomatoes she has canned. Her monthly income is $119 from social security.

``My daddy fought in the Civil War,'' she says. ``All my family is gone but me.'' A widow for 18 years, she has spent most of her time at home alone, sometimes playing solitaire.

But for the past few years, she has found new joy at the senior center. ``I don't know what I'd do if it wasn't for that,'' she says. The people there are ``all my friends. I love them all.''