What is "bartering?" Jack knew the answer when he traded his cow for the beans which grew into a tall green beanstalk. Jack and the Beanstalk is just a story, but people are trading like that every day. Bartering is another word by trading or swapping. We are bartering when we swap a baseball for a blue frisbee, or when we trade away our property in a Monopoly game. Barter is a way to get things without paying money. We pay in a different way; we pay by giving something of our own, or by doing work for another person.

If we didn't barter, we would need money to buy things. And we would get that money by working -- or by selling something, like our game or our old white basketball shoes. Then we could spend the money. But sometimes we are broke. At times like that, it's smarter to barter.

In this book, we will visit the imaginary city of Barterburg. You won't find it on a map; it doesn't exist. But in this story, the people of Barterburg are just like us. And the things which they say about bartering are true. In Barterburg, everyone trades, so the kids know a lot about it. We can learn from them.

"Last summer, I started to trade with my friends," said black-haired Sam Rodgers, who lives in Barterburg. "Before then, I could get something only if I spent money for it. But sometimes I didn't have enough money. And there wasn't anyplace to earn it. Then I learned how to barter. Now I can get some of the things I want, even when I don't have cash."

We have many things which we can trade. We can swap the old stuff which we don't want any more. Some of those things might be the T-shirts and pants which we have outgrown. Our toys and sports equipment can be bartered, if we don't want them. We might trade our Schwinn bicycle, and our old computer monitor, and the ping-pong table which is in your dusty attic.

When we barter away our old things, we will get something wonderful. We might get a better bicycle, or some computer programs, or an oil-painting set. Maybe we will get a baseball or a music CD, or a pair of black ice skates. We might find someone to give us some lessons in skiing, or website design, or nearly anything else.

"I didn't think that anyone would want my banjo," a Barterburg girl told me, as she showed me a beautiful silver pendant, "but my girlfriend wanted it. She gave me this pendant for the banjo. I'm going to trade something to get her other jewelry, too."

"I have a collection of jewelry from foreign countries," she said. "I got a Russian ring by trading a calculator to a girl named Eva. Eva was from Russia. She could speak English, but she couldn't read very well, so I gave her a reading lesson every Sunday. It was easy. And we are good friends now."

The girl has traded some things which we could trade. She said, "When I got tired of my tropical fish, I swapped them for three summer dresses from my cousin Janet. She couldn't wear the dresses any more, so we both got rid of things we didn't want. And we got stuff we did like."

If we barter, we might find someone to repair our broken clock, or give us a ride to Portola Park. The trader could help us with our history homework, or do other things which we want. One girl advertised in a newspaper to find someone who would train her furry pet raccoon. Instead of paying cash to the raccoon trainer, she taught him how to make a database on his website.

"You can't get everything by bartering," I was told by Billy Eastus, a fifth-grader in Barterburg. "There are people who trade -- but if you don't have what they want, they won't trade with you."

Billy was correct. For instance, maybe we want the metal ladder which is in Jackie's back yard, but she doesn't have any use for our .22 rifle or the other stuff which we want to trade away. At times like that, we have to pay cash. But many people do trade.

Bartering is fun, but it can be a serious business, too. Thousands of businesspeople barter every day, to get things without spending money. A car mechanic might fix a plumber's Ford van, and then the plumber will unplug the mechanic's bathroom sink.

Everyone barters. People did it back in the days of George Washington, and in the days when Columbus was sailing across the stormy gray Atlantic Ocean. They even bartered in the days when cavepeople lived. In those times, long ago, there was no money; no one had dollar bills, or bank checks, or pennies. People traded one item for another. You would trade your arrowheads for my freshly killed dear, or your moccasins for my delicious corn. Since those ancient times, people have always bartered in one way or another.

As we learn more about money and barter, we know why barter can replace money sometimes. It is especially good in a kid's life. After all, this is a grown-ups' world. They have nearly all the money. And they usually say how much money a kid can spend, and what the kid can buy with the money.

You are too young to get a full-time job, so you need to barter, to get things without a job and without money. A 10-year-old boy in Barterburg said, "The only cash I get is my allowance, and the money which my parents give to me. I don't get anything if they're in a bad mood, or if they can't afford it."

That boy learned how to make wood carvings at summer camp in Illinois. Now he swaps his carvings. He traded a wooden letter-opener to his brother, John, for a computer book. When he carved a lamp for his sister, she let him use her 10-speed bicycle for a week. "I love to barter," he said, "because my friends and I never have much money. But if we barter, we can get what we want, even when we are broke."

He went on: "When my parents have bills to pay, they can hardly afford to give me an allowance. But my Dad joined a barter club, so he can barter with other people. Now, for my allowance, sometimes he gets me things instead of money. I was saving up for a sled, but my Dad couldn't afford my allowance for three weeks in a row. He felt bad about that, so he found someone in the club who could give me a sled. To pay the woman for the sled, my Dad fixed the brakes on her truck."

When you become an adult, you might barter for a swimming pool in your back yard, and other things which adults get by bartering. Then you can teach your own kids the lessons you've learned, so they can barter, too.

You will whisper the secret in their ears, "You can trade for almost everything you want."