Mayan Calendar

22 23 The numBering sysTem fingers and toes The counting system we use today is called place numeration, in which there is a position for units, and further placed positions for multiples of those units. This ingenious technique is thought to have originated in India around the 8th century, passing via Arabia to Moorish Spain. However, we now know that place numeration and the concept of zero had already been in use in Mesoamerica for over a thousand years. Our decimal, or base10 system, has units, 10s, 100s, 1000s, and so on the Maya instead used a vigesimal, or base20 system, with units, 20s, 400s, 8000s, etc. In our decimal system, the positions increase by a factor of ten from right to left, and are read from left to right. In the Mayan system, the positions increase by a factor of twenty from bottom to top, and are read from top to bottom. There is an exception when recording dates in the long count calendar, the third position represents only 18 times the second position, giving a 360day unit instead of a 400day one, and thus approximating the solar year. The Maya used three types of notation for recording numbers. These were the baranddot numerals opposite top, the rarer headvariant numerals see caption opposite top, and the very rare fullfigure glyphs lower opposite. Zero is represented by a shell glyph in the codices, and by half a quatrefoil flower below in the inscriptions. The full quatrefoil represents the 260day calendar in the Fejervary Codex and the Madrid Codex see page 27. The dotbar system probably originated using stone, twigs and seashells, with a stick representing the number 5. In the headvariants a different human head represents zero to twelve, except for ten, which is a deaths head or skull. For the teens, thirteen to nineteen, the heads of numerals three to nine are used with an additional fleshless jawbone from the skull of number ten. Full figure glyph numerals depict the heads with bodies attached. For example, zero uinals is a man with a forehead attachment and a handjaw zero shown wrestling with an amphibian uinal. introductory 9 baktuns 15 katuns 5 tuns 0 uinals 0 kin 10 Ahau moon phase 8 Chen undeciphered