A letter in today's mail says, "Thank goodness you're still here to do one more Children's Hospital campaign, and that I'm still here to read about it."

Amen, sister. I don't know your age, or what your health problems are, but I like your outlook on life. One never knows what tomorrow will bring, so it behooves us to hope for the best, prepare for the worst, and be grateful or every day of life that's given to us.

After I finished yesterday's tally of gifts to Children's Hospital, a colleague said, "The average gift from individuals was more than $30. Is that a fluke, or will it continue to run that high throughout the campaign?" My answer to him was, "Statistics don't mean much. The averages fluctuate."

If you're curious, take a closer look. The 79 individuals who gave $2,580 yesterday averaged $32.66. But the most popular amount on my list was $10, closely followed by $25.

The complete breakdown shows 11 gifts of $5 each, 21 at $10, seven at $15, six at $20, 18 at $25, one at $30, two at $35, one at $40, seven at $50, two at $100, one at $150, one at $300 and one at $500. Obviously, a few large gifts pull up the average for the entire list.

By coincidence, there are als/ 79 gifts from individuals in today's report, but they add up to $3,677.01 and their average is $46.54. Today's tally sheet shows one gift of $2 followed by 13 at $5 each, 17 at $10, one at $14.01, five at $15, one at $17, one at $18, eight at $20, a dozen at $25, one at $27, two at $30, one at $34, one at $35, one at $40, five at $50, one at $60, six at $100, one at $250, and one blockbuster from Florida for $1,500-the largest gift from an individual I have ever received.

It is obvious that on days when there are no large gifts, the average drops. But $10 and $25 contributions are always the most numerous.

In case you're wondering about some of the odd amounts, let me tell you about the reasons people give. In accompanying letters, they explain:

"I found this on the street in an envelope with no identification."

"I helped because I wanted to help, not for money, and when they insisted on my taking the money I said I would send it to you for Children's Hospital."

"This is my birthday present to myself - one dollar for every year of my life."

"In Hebrew, Chai means 'life,' as in I'chayim , 'to life,' and Chai also means 'eighteen.; For this reason, gifts to charity are sometimes in the amount of $18, a symbolism that is especially appropriate for a gift to Children's Hospital."

"This is the money I made baby-sitting."

"This check for $27 represents the 2,700 pennies I saved up during the past year."

The $14.01 listing was also for a penny collection-one brought up from Florida by a woman visiting relatives here. She brought me more pennies than I could get into a one-pound coffee can. My bank counted and wrapped them by machine and gave me paper money for them.

Checks from individuals always out-number group gifts during erly December, but we do have eight checks from groups today. The Columbia Chapter of the Child Study Association sent me $5. Members of the Foreign Demographic Analysis Division of the Census Bureau refrained from exchanging $12.50 worth of holiday cards among themselves. "The Bridge Girls of Orleans Way" contributed $25. No card exchange in the Defense Product Engineering Services Office at Cameron Station netted $36 for the hospital.

A check for $38 arrived from Indian Head, Md., with the identification, "from the Potomac Heights 'Leisure Club' Senior Citizens." The Riverdale Hilss Women's Club remembered the children again this year; its check was for $50. And from the Fair Lanes bowling centre in Prince George's Plaza came $70 contribyted by the Area Church Bowling League.

Biggest group gift of the day was $188 form the firefighters of Truck 3 and Engine 16 of the D.C. Fire Department-the lads at 13th and K streets NW. "Happy Holidays," they wrote, "and stop by for a cup of fire-house coffee when you're in the neighborhood." Sorry, fellows. I still get icicles on my nose watching you knock down fires in freezing water, but I'm not allowed to drink real coffee anymore. First I wasn't old enough to drink it, now I'm too old. ..Bah! Humbug!

Group gifts come to $424.50 as I count them. Add the $3,677.01 from individuals and we get a total of $4,101.51 for the day. To date, $12,436.55 has accumulated in the shoebox.