Numeración maya y biografía de bessie head

El sistema numérico de puntos y rayas
En el sistema de numeración maya las cantidades son agrupadas de 20 en 20; por esa razón en cada nivel puede ponerse cualquier número del 0 al 19. Al llegar alveinte hay que poner un punto en el siguiente nivel; de este modo, en el primer nivel se escriben las unidades, en el segundo nivel se tienen los grupos de 20 (veintenas), en el tercer nivel se tienelos grupos de 20×20 y en el cuarto nivel se tienen los grupos de 20×20×20.

Numeración maya.
Los tres símbolos básicos son el punto, cuyo valor es 1; la raya, cuyo valor es 5; y el caracol (algunosautores lo describen como concha o semilla), cuyo valor es 0.
------------------------------------------------------------------------------------------------------------------------
Bessie EmeryHead was born in Pietermaritzburg, South Africa, the child of a wealthy white South African woman and a black servant when interracial relationships were illegal in South Africa. It was claimed thather mother was mentally ill so that she could be sent to a quiet location to then give birth to Bessie without the neighbors knowing. However, the exact circumstances are disputed, and some of BessieHead's comments, though often quoted as straight autobiography, are in fact from fictionalized settings.
In the 1950s and '60s she was a teacher, then a journalist for Drum, a South African magazine.In 1964 she moved to Botswana (then still the Bechuanaland Protectorate) as a refugee, having been peripherally involved with Pan-African politics. It would take 15 years for Head to obtain Botswanacitizenship. Head settled in Serowe, the largest of Botswana's "villages" (i.e. traditional settlements as opposed to settler towns). Serowe was famous both for its historical importance, as capital ofthe Bamangwato people, and for the experimental Swaneng school of Patrick van Rensburg. The deposed chief of the Bamangwato, Seretse Khama, was soon to become the first President of independent...