MAYAN NUMBER SYSTEM
The Mayan's number system was based on the number 20. Our number system is based on 10. Why did the Mayans use the number 20? A number system doesn't function unless the number zero is included. The Babylonians knew about the concept of zero. The Hindus invented zero about 600 BC, the same time the Central American zero was invented. The Central American zero was used for thousands of years before it was used in Europe. Mayan numbers were easily used for additions and subtractions, much easier than using Roman numerals!
Mayans used only the following three markings for numbers:
crossline: meant five,
dot: meant one,
stylest mussel: meant zero.
Every number was expressed with combinations of lines, points, and zero marks, using system of place values. The modern marks divide figures into tens, thus the value increased from right to left. Mayans counted in twenties and the value increased from bottom to top in vertical columns; at the lowest point of the column, unit marks were ones, but on top were four-hundreds place (like 20*20). However, the Mayans could not express fractions.
Some mathematical names for days:
1 day = kin
20 days = uinal
18 uinals/360 days = tun
20 tuns/7200 days = katun
20 katuns/144000 days = baktun