An Ethnomathematics Case Study of Candrasengkala: A Reversed Order Chronogram in Bali-Java Tradition

Abstract

Chronogram is a method to represent year by using a phrase. It is known in some cultures in the world, including Indonesia. Not only to record years, chronogram also be used as an encryption code in ancient cryptography. The present study aims at explaining the chronogram practiced in old Bali and Java traditions called Candrasengkala. Specifically, this is an ethnomathematics case study to understand how indigenous people of Bali and Java, two closely related cultures in Indonesia, practicing their ancient chronogram. To gain the data, we employed literature review and expert interview method to deeply learn the relation and arrangement among the numbers in Candrasengkala. The collected data were analysed qualitatively using descriptive method. From the analysis, it was found that Bali-Java chronogram performed a unique place value system. It means the represented year in Candrasengkala is written in ascending (unit-tens-hundreds-thousands) rather than descending (thousands-hundreds-tens-unit) order which is commonly used nowadays.