Yupana
Yupana was a calculating tool used by the Incas and probably resembled the abacus in its function . The word is Quechua and literally means to count.
José de Acosta was one of the first to describe the use of Yupana in his work Historia moral y natural de las Indias (Seville 1591). In it he wrote that grains of corn were placed in the boxes of the Yupana and that the Indians carried out the calculations with astonishing speed. The Incas then noted the numbers in the Quipu number script as knots on ropes. An illustration of a Yupana with a quipu can be found in the chronicle l primer nueva corónica y buen gobierno by Waman Puma de Ayala (around 1615). However, neither there nor at De Acosta is the exact function of the Yupana explained, so that this is still the subject of speculation today. In addition to the illustration at De Ayala, there are archaeologically preserved specimens of Yupanas, but they are not structured uniformly. In the illustration at Ayala, the boxes are filled with one to five black and also with white circles. A common interpretation assumes that a decimal system is used. In 1931 Henry Wassen assumed that the rows progressed in powers of ten and the columns in the progression 1, 5, 15, 30, so that, for example, three black stones (corn kernels) in the first column of the bottom row represent a 3 and one black in column 2 a 5. But there were also other suggestions. According to Burns the arrangement of the rows is as in Wassen, there are a maximum of five stones in the first column, three in the second and two in the third (with a maximum of 10 stones in each row). According to Burns, the fourth column in the figure is for registration only.
literature
- Molly Leonard, Cheri Shakiban: The Incan Abacus: A Curios Counting Device , University of St. Thomas, Minnesota ( pdf )
- Mathematics Across Cultures: The History of Non-Western Mathematics , edited by Helaine Selin, Springer 2000
- Thomas E. Gilsdorf: Introduction to cultural Mathematics , Wiley 2012
- William Burns (William Burns Glynn): La Tabla de Cálculo de los Incas, Boletin de Lima, No. 11, 1981, pp. 1-15
- M. Ascher, R. Ascher: Mathematics of the Inca, Mineola 1997