“They had asked us to do a Hanukkah-themed book, because we are Jewish,” Mr. Weber said. “So I went in today and read a book illustrated by Syd Hoff, ‘A Chanukah Fable for Christmas,’ and it’s all about a kid who grows up in the Bronx, but all his friends celebrate Christmas, so he’s sad. And so he learns how everyone has holidays around this time.”

Mr. Weber used the visit as a chance to share stories of being a Jewish child among Gentiles.

“I started by saying that when I was a kid, growing up in Brooklyn, most of my friends were Catholic,” Mr. Weber recalled. “I was sad because I didn’t get to celebrate Christmas.” But as he got older, he told the children, he realized that Hanukkah was a special time, too. “The conversation I started with kids was it’s a holiday time of year, whatever holiday we are celebrating, and the importance is to spend time with family and friends.”

In general, public schools may teach about religion, but are not to preach or encourage religious practice. But what does that mean in a country where Christmas has become so much a part of secular American practice, where its songs are part of the American songbook, where it is a shopping season as much as a sacramental one?

Inviting Jewish parents to Hanukkah-splain can be a hedge against charges of Christian favoritism. Rather than eliminate “Jingle Bells” and “Rudolph the Red-Nosed Reindeer” from the holiday pageant — which, let’s face it, would be no fun at all, and would displease plenty of Jewish children, too — one compromise is to raise high the menorah.

“At the school assembly, where they sing holiday songs, last year they asked us to be part of it and light the candles,” said Danny Glusman, a Jewish father of four from Atlanta. However, he said, the teachers at his children’s charter school are not of one mind about religion. This year, when one of his daughters brought a Hanukkah menorah to her classroom, the teacher asked her to put it away because it was a “religious item.”

“I think they are confused,” Mr. Glusman said. “There are Muslims, Jews, some Hindus, and many of the teachers are just nervous about doing the wrong thing. Our kids are learning not necessarily Christmas songs, but holiday songs, not ‘First Noel’ or ‘Silent Night,’ more ‘Jingle Bells’ or ‘Winter Wonderland.’ But they see it as we don’t get to sing our Hanukkah songs. So this year, the music teacher asked me to send over some Hanukkah songs to teach everybody.”

Hanukkah-splaining can, however, provoke kvetching from Jews, Gentiles or atheists. Purists about the separation of church and state would prefer less religion in the classroom, so adding a religion to the mix is not considered progress. Jews may feel, rightly, that focusing on Hanukkah conveys the misimpression that Hanukkah is as important, religiously, as Passover or Purim.