This article is brought to you by the years 250 to 900 CE!

You watch the clock.  Your stomach is making lots of noise.  You can see your friend laughing at the strange noises out of the corner of your eye, but it does not matter.  You can't wait for lunch. 

Finally, the bell rings, and you walk as fast as you can to the cafeteria.  You sit down, take out your lunch, and"¦

"Oh, no!  Not peanut butter again!"

Lucky for you, your friend does not like his turkey sandwich and you agree to trade sandwiches. 

Think about the reasons behind why you traded your sandwich.  Your mom may have packed peanut butter, but that wasn't what you wanted to eat today.  You eat peanut butter all the time!  You wanted to shake things up, and so did your friend. 

Trades like this have happened for thousands of years, all over the world.  The Mayan civilization used to plan trades like this too.  People from all over would come together to meet and trade goods, as well as news from different areas.  Instead of just one sandwich, hundreds or even thousands of people would be exchanging many different goods -- everything from clothes to weapons.  They would not just make these trades over lunch tables, but would all gather in order to trade in a central place in their cities.  Markets were the places where people met to trade. 

Pretend that you are trying to keep up with thousands of sandwich trades -- who was trading the sandwich, what kind of sandwich it was, where the person was from.  It would be really hard to keep track of the trades if you could not write them down!  The Mayans had to keep track of all the trades at the markets, but, at first, they didn't have a way to record them.  So they made one of the first forms of writing so that they could keep track of the trades that were done at the markets.  This was really important because it kept their markets going, but it also helped make them stronger. 

You wanted to trade your sandwich because you had already eaten plenty of peanut butter.  Just like you had enough peanut butter, the Mayans had more than enough of some things, but not enough of others.  It worked out really well for everyone, because other people in other parts of the empire wanted these extra goods.  After all, they couldn't make them all themselves. 

If you lived in the flat part at the bottom of the mountains of the Mayan land, the weather and the soil were ideal for growing plants.  People who lived here would grow plants you could make into cloth.  This was really important -- without cloth, you would have a hard time making housing or clothes, both a key part in helping a people stay alive.  Cotton is the name of the plant used to make cloth. 

Cotton plants were not the only crops to grow at the bottom of the mountains-- plants for eating also grew very well there.  Sometimes Mayans wanted to eat different foods.  Think about if you ate only bread for a day -- you would be ready for some ice cream by dinner, right?  If Mayans wanted to eat fancy dessert, they would use plants like cacao, which is used to make chocolate. 

The Mayan empire was huge, so not everyone could live at the bottom of the mountains -- some people decided to live on the mountains.  It would be really hard to grow plants for eating or making clothes on a mountain, because they were covered in many different kinds of rocks.  It might sound a bit crazy, but even rocks played a key part in people's' lives!  They might use them to make their homes look nicer or to make necklaces or bracelets.  Jade is a beautiful, pale green stone that could be used in art. 

Mayans also used rocks for hunting or for weapons.  They would not use just any rock.  Only special rocks were sharp enough to kill animals for food or keep people safe from attack.  Their weapons were often made of obsidian, which is a kind of hard, black glass that can be made super sharp and comes from volcanoes. 

Just like your friend did not want his turkey sandwich, the Mayans at the bottom of the mountain did not need all their cotton -- they had more than enough cotton to make their clothes.  Those people did not live near any volcanoes, so they had nothing to make weapons from and could not defend against an enemy attack.  If they wanted to make weapons, they would have to trade some of their cotton.  People on top of the mountain had plenty of weapons -- but they might not have been able to grow plants to make clothes, and that might be a problem as soon as winter rolled around.  Everyone had to trade to be happy, and more importantly, to have what they needed to live. 

The markets were a great way for everyone to get what they wanted.  Still, think about if you and your friend were sitting on different sides of the room.  Instead of just handing it across the table, you might have had to pass your peanut butter sandwich down through a huge chain of people, until you could finally bite into the turkey sandwich that you wanted all along.  Of course, if you lived in the Mayan empire, you might have been at the top of a mountain, and your friend might have been at the bottom.  In order to get goods to the markets, Mayans had to build many trade routes.  They also had to build roads and bridges and keep them safe from crime. 

It was important for the Mayans to trade so that different goods were spread around equally, and everyone could wear clothes or defend their homes.  Trading was good for the Mayans, just like it made you and your friend happier at lunch.  More importantly, though, trading made people come together, even though they lived far apart.  They had to make a language that everyone spoke and a form of writing that everyone could read, no matter where they lived.  This way of talking, on top of the strong markets, is what helped the Mayans to become great.