Base 20 Numbers

Cozumel, Mexico

We drive around the Island and park the rented jeep on a dirt road in the jungle. Alfredo steps out of the jungle and offers to be our private guide to the pyramids and ruins. We are alone here with him. He has a clipboard.

Before we start down the trail Alfredo announces that he is of Mayan ancestry and tells us that the Mayans were very advanced and, for example, used the base 20 numbering system. Alfredo begins to teach us base 20, using his clipboard.

They had 20 symbols for numbers. They had a zero and 19 other symbols (dots and lines).

They stacked their numbers. The first row would represent the numbers zero though nineteen.

The next row up used the same symbols but had place values of 20, then 400 then 8,000.

For example:

1 * 8000 = 8,000
3 * 400 = 1,000
2* 20 = 0
5* 1 = 5

So the total is 9,045

The year 2008 would be written as:

5 (The symbol for five is a horizontal bar)
0 (Zero looks like a toothy smile)
8 (Eight is three dots over a horizontal bar)

Alfredo challenges us to express the current year in base 20.

I write the answer:
4 = 1,600 (four dots)
19 = 380 (four dots over three horizontal bars)
16 = 16 one dot over three horizontal bars)

Satisfied that we are worthy, Alfredo leads us to the ruins. He has a collection of documents that helps to explain what we are seeing and how this sacred place was used to worship Ixchel, the Moon Goddess. All Mayans were expected to make a pilgrimage here once in a lifetime. We wonder what forces drew us here for ours.

Later we stumble upon a remote festival in a tiny town. It is a Cinco de Mayo celebration. There is a bullfight. We are the only tourists. It’s a little like a county fair without the rides, 4-H exhibits and Italian sausage vendors.

Later we stop on a wide, white sand beach in a solitary tent restaurant for margaritas and cheeseburgers.

We pick up two young hitchhikers for the long ride around the island back to town. On the lonely jungle road, a squad of soldiers with sub-machine guns wave us to a stop. They don’t speak English. Our hitchhikers talk to the soldiers and they wave us on. The hitchhikers tell us that four divers were lost yesterday, sucked down the wall by kind of a downdraft flushing action. One was a divemaster who was reported to be last seen chasing three foolish touristas. The soldiers just want to know if we’ve seen any bodies or dive gear washed up on the beach.

The next day we dive the wall. Mrs. Phred wants to stick close to the Mexican divemasters. I tell her if they look like they're getting flushed, we're out of there, rules or no. The towering pillars of coral are like nowhere else.