DEAR ABBY: I have some advice for “Lacking Why,” the girl in your Oct. 18 column who is wondering why the amount of allowance money Grandpa gives her and her sisters varies from one girl to the other: Stop comparing the amounts and try focusing on how attentive each of you is to your grandfather.

Do you all visit him with the same frequency? Do you all write thank-you notes for his generosity? Do you all phone him the same number of times each week? Do you all remember his birthday with a nice card or small gift? Do you take turns baking him a birthday cake?

I suspect, as with my grandchildren, there are wide disparities in the way these sisters treat Grandpa. Why would a person who ignores him expect the same generosity as one who showers him with love and affection? I have two grown grandkids who treat me differently and, son of a gun, I respond in kind.

— CONNECTICUT GRANDMA

DEAR GRANDMA: Your explanation is one I received from other readers as well. That letter resonated with a large number of people, and what follows is a sampling of their responses:

DEAR ABBY: Financially speaking, I’ll bet there’s a good reason for the disparity in the amounts “Lacking” and her sisters receive. If Grandpa intends that each granddaughter receive the same sum of money by age 18, and he started giving the money to each of them at the same time, he would HAVE to give them different amounts. This concept would be hard to explain to a child, which may be why the girls were never sure about the “why.”

— NUMBERS GUY IN SAN MATEO, CALIF.

DEAR ABBY: My father did the same thing. Each year I received more money from my dad than my brothers did. Eventually I asked him why, and it turned out he felt that over the years he had helped them more in other ways. They had lived at home longer than I had, and Dad had paid for their educations while I’d had a scholarship.

In his mind, he was trying to even things out. Funny thing was, it didn’t matter to me. But I never told my brothers.

— SOLVED THE PUZZLE

DEAR ABBY: The mother of those girls should be the one to broach the subject with her father. She can soften the response to her daughters and point out to her father the possible harm he may be causing within the family. But in the end, if Grandpa doesn’t budge, they’ll all have to learn to live with it.

— KEN IN SARASOTA, FLA.

Write Dear Abby at www.DearAbby.com