They are donors named Anderson. But they share a worthy purpose as well as a surname -- to help sick kids at Children's Hospital get better.

Our first generous Anderson is Gwen, of Burke Centre. She sends a donation to our Children's Hospital fund-raising drive each year about this time. And she always calculates the amount according to the same formula.

Gwen's gift this time is $29. That represents a buck for each year of her grandchildren's ages, plus a dollar for each "to grow on." Gwen says she again makes her donation in gratitude for the good health of John Watson, now 15, and his 12-year-old sister, Shannon.

Meanwhile, across the river in Wheaton, Byron and Ruth Anderson say they have seven "of the most adorable, loving, precious grandchildren in the entire world." So Byron and Ruth did essentially what their Virginia counterpart has long done. They sent in $55.15, which represents the combined ages of their Magnificent Seven (the 15 cents represents a newborn).

Other Andersons are encouraged to follow suit. But so are Smiths, Joneses and Whatevers. Grateful grandparents have long been a mainstay of our drive. Obviously, 1990-91 is no exception.

Elsewhere in our Children's Hospital mailbag . . . .

A CONSCIENTIOUS COLLEGE STUDENT: Alia G. Carbone, of Burke, says she has wanted to contribute to our holiday season drive "for years." But for most of that time, she was a high school student without a checking account. So "it always seemed like too much trouble."

Not this year. Alia is a freshman at Virginia Tech in Blacksburg. Wonder of wonders, she has a checking account -- which is now $11.27 lighter, for the benefit of the kids at Children's Hospital whose families are too poor to pay their medical bills.

And get this: Alia's donation didn't come from the pizza or the ice cream fund. It came from her "graduate school fund piggy bank." Extra thanks for that, my friend. Any copycats out there in the groves of academe?

A LUCKY LIBRARIAN: Susan Collins, of Charlottesville, was sorting through donated books at the Jefferson-Madison Regional Library when a 5,000-cruzeiro Brazilian note fell out of a novel. "We decided to send it to you," Susan writes.

I'm glad she did, for the bill is worth approximately $38, according to the Brazilian Embassy. Susan's lucky discovery proves once more that foreign money is an excellent source of "found funds" for our Children's campaign. If you have foreign coins or bills, mail or bring them to me at the address that appears at the end of today's column. I'll see that the money is converted to U.S. dollars for the benefit of our campaign.

A BUDGET-CONSCIOUS NEWLYWED: Helen Kuhnsman, of Riverdale, married a "wonderful state policeman" six months ago. They soon bought a house, which can put large holes in any budget.

But Helen was determined to send $30 to our Children's campaign just the same. Her price: that I publish a poem she has written in honor of her husband. I'm delighted to comply.

Keith Trooper Bear

Six months in heaven, kisses and smiles

A little yellow house, a big fat mortgage

I'd do it all over again

I love you!

A DEDICATED SENIOR CITIZEN: That would be Theresa Plummer, of Catharpin, Va., an annual giver to our Children's campaign who has again earned that description with a $10 check despite pressures in the other direction.

"I am on a reduced and fixed income right now, and have had to drop some of my charities," Theresa writes. "But Children's Hospital is not one of them."

May it never become one of them, Theresa. Thanks from the heart.

AN HONEST MAN: "I hate Christmas," writes Doug Fuller, of Fairfax Station. And why might that be, kind sir?

"It's the gift-giving I hate, particularly for my mother, father and sister," Doug explains. "It seems that anything I give them is put away, never to be seen again. I can never get them things they really need."

So Doug has taken a different tack this year. He is donating $40 to three charities that his family members deem worthy.

Is Children's one of the beneficiaries? It sure is, thanks to Melinda Fuller, Doug's mom.

Hats off to both Fullers, but especially to Doug for giving renewed meaning to the spirit of Christmas. Another tie-dyed scarf would not have done the trick. A gift to Children's always does.

TO CONTRIBUTE TO THE CAMPAIGN:

Make a check or money order payable to Children's Hospital and mail it to Bob Levey, The Washington Post, Washington, D.C. 20071.