Like their public school counterparts, teachers in Jewish schools around the country have been banning Pokemon trading cards from the classroom.

I can't help wondering whether they are missing a golden opportunity.

For adults to understand how this ban has affected the average second-grader — for example, my son, Noah — they need only to imagine their own bosses banning something they value. Like breathing. Or eating.

Pokemon (pronounced po-KAY-mon) is a $5 billion-and-counting cartoon empire that includes a television series, video games, action figures, a series of trading cards, and now a high-grossing movie.

Pokemon — or "Pocket Monsters" — is a universe of pint-sized beasts that fight in teams assembled by their human "trainers." The trading cards feature pictures of the characters, and baffling descriptions of their fighting strengths and weaknesses. The rules to the card game tend to be in a syntax that you suspect might make more sense in the original Japanese: "Only Energy of the appropriate kind counts toward Energy requirements of that kind."

I have had an easier time translating a page of Talmud than deciphering my son's cards. My ignorance astounds him.

My son and his friends are less interested in playing the game than in merely trading the cards, and here is where the marketer's genius is revealed. There are 154 individual pocket monsters, not counting trainers and "energy" cards.

Cards cost about $5 for a set of 11 — or at least they did before local comics dealers started doubling and tripling the prices in response to demand. Each set has only one or two cards that the kids really value, leading some parents to sue the makers on the grounds that they are running a preteen lottery.

I suppose I should cluck my tongue about the detestable marketers who target susceptible children. And maybe I should applaud the teachers for keeping distractions out of the classroom.

And yet, Pokemon gave my son a quickie education in Economics 101. Before the Pokemon craze, he had the usual 8-year-old's grasp of finances — "a lot of money" was a catchall term to describe anything from 85 cents to $10 million.

Thanks to Pokemon, he now understands value, supply-and-demand and, most of all, the volatility of the market place. In the early stages of the fad, he had no idea what a Pikachu or Bulbasaur could fetch on the open market.

Older kids were taking advantage of the younger kids, trading junk cards for high-performing commodities like Charizard and Blastoise. Within weeks, however, the word "rip-off" had entered Noah's vocabulary. He even began hovering protectively around his younger brother, an easy mark for a fourth-grade predator. I wish I had as good an adviser the last time I bought stock.

Instead of banning the cards, imagine bringing them into the school curriculum — especially at a Jewish day school.

The cards could serve as an introduction to the concept of ona'ah, or "just price." Rabbinic law codes are strict about preventing over-charging; they allow buyers and sellers to renege on a transaction if the agreed-upon price turns out to have been egregiously high or low (see the Mishnah, Baba Metziah 4:3).

If, however, both parties know the seller is charging well above the market price, there is no fraud. I can demand a Dratini, Growlithe and Rapidash for one "holographic" Japanese Wheezing card, so long as you know you can get a better deal elsewhere.

In some cases, the rabbis left room for merchants to charge what the market will bear. In real estate, for example, one person's shack is another person's castle, and both the seller and buyer beware.

Still, the rabbis do come down hard on merchants who jack up prices for customers who are under duress. Whether this applies to a card dealer staring across the cash register at a wild-eyed 7-year-old is matter for the gedolim, or rabbinic sages, to decide (and second-graders to discuss).

Jewish schools have long been criticized for building a wall between the secular topics and the religious curriculum, creating separate moral universes. But it's more than a school problem. How many Jews make the connection between what they read and say in synagogue and the activities they carry out the rest of the time?

This is not just a rap on religious Jews, who get beaten with the stick of hypocrisy infinitely more times than they deserve. It's also a challenge to so-called "secular" Jews who ignore the inherent holiness in their work-a-day transactions.

Think of the merchant who proudly declares "I'm not religious," but would no more overcharge a customer than would a Chassid eat a pork sandwich. Maybe, just maybe, he would engage more seriously with Judaism if someone had pointed out that holiness is a category of work and leisure, not just prayer.

I cringed the first time my son took out his Pokemon cards at synagogue. But as he and his friends began to learn the vagaries of the marketplace, and parents kept a discrete watch that neighbor was not oppressing neighbor, I could relax.

These kids were doing what they were supposed to be doing in synagogue: learning how to be moral human beings. You can't put too high a price on a lesson like that.