INTERNATIONAL JOURNAL OF SCIENTIFIC & TECHNOLOGY RESEARCH VOLUME 6, ISSUE 09, SEPTEMBER 2017 ISSN 2277-8616 325 IJSTR©2017 www.ijstr.org Ethnomathematics In Arfak (West Papua- Indonesia): Numeracy Of Arfak Haryanto, Toto Nusantara, Subanji, Swasono Rahardjo Abstract: This article discusses ethnomathematics in Arfak indigenous communities. The focus of this research is how to calculate Arfak society in the form of the language of the hatam. The purpose of this study is to know the type of numbers in the language hatam by people in everyday life in the calculation and then look for the addition of algorithms according to the type of number. The method used in this research is ethnography. Next searched the addition of algorithms that match the type of numbers used by the community. The results obtained in this study are the numbers in the language hatam using base number 5-10. Of the numbers obtained, the appropriate summation algorithm is Abacus 4.1. Keyword: ethnomathematics, arfak, numeracy, abacus. ——————————  —————————— 1 Introduction Ethnomathematics is the practice of mathematics in cultural groups. The cultural group referred to them are urban or rural communities, working groups, professional grade, students in groups, indigenous peoples, and other specific groups [1]. Whether consciously or unconsciously, all of the human activities in the world are done based on an appropriate calculation that is suitable to the condition of nature where they live. The research is related to ethnomathematics such as, mathematics in patterned creation in Congo [2], Mathematics in traditional games in Nigeria [3]; calendar system of Indian also has mathematics science that is similar with Mayan ethnic [4]; African mathematics facilitates mathematical concepts [5]. The relation of art and symmetry of geometry in Africa [6], Mathematics science in basket handicraft of muzambi in Southern Africa [7], and Mathematics science in a puzzle game in Nigeria [8]. ethnomathematics is very effective. It can be proved by many studies, such as Orey and Rosa [9], Muzangwa [10, Fyhn [11], Narayanan [12], and Achor [13].Indonesia is one country in Asia with a population that is multi-cultural. Of the various cultures that exist in Indonesia, the islands of Papua region is an area with many cultures. Papua region is made up of two provinces with more than 200 tribes. This is because the areas in Papua, especially in the interior hinterland is still difficult to reach. Isolation of this area led to the unique insights that develop in any area or inland. One of the unique knowledge is knowledge of math. Arfak Mountains Regency is a division of the district of Manokwari, West Papua Province. This district includes the rural areas and mountains in West Papua. Because this area is largely mountainous, it is difficult to access by land vehicles. in fact, there are many villages that are only accessible by air or on foot. Limitations that causes areas still isolated from the outside world. Therefore, the cultures of the Mountains Arfak much remains contaminated from the outside world. Ethnomathematics in Papua island has many unique. The following ethnomathematics studies in the area, elasticity noken bag due to changes or shifts knot - a knot of yarn cross sections with one another [13]. Arfak society in the determination of the nodes in the framework of the floor and wall frame house centipede own use properties - properties of triangles, these properties are used to calculate the strength, endurance, stability of home [14]. System numeracy Arfak society in hatam language using the base number-5-10 it is different from the mathematics school which uses a base 10 [15]. Aside from the hatam language communities in the count finger motion using only three fingers of one hand [16]. In this article will be explore ethnomathematics of Arfak community about algorithms addition and subtraction of natural numbers that correspond to the type of society Arfak numbers. This needs to be researched for different types Arfak numbers with mathematics in school, especially in Indonesia and the world at large is using Hindu-Arabic numbers. Hindu-Arabic numbers using the base number 10. 2 METHODS The method used in this research is by way of exploration, interviews and literature studies. Exploration and interviews were conducted to obtain numeracy used by the public Arfak. The literature study done by finding numeracy-numeracy which have similarities with numeracy Arfak were then determined how or algorithms in resolving the binary operation. The algorithm searches done by looking at the culture of other regions that have the properties - properties of the same number. 3 RESULTS 3.1. The number system Arfak on hatam language. Hatam language is used by people Arfak. The mention of numbers is as follows: ___________________________  Haryanto is Doctoral Student in Universitas Negeri Malang dan Lecturers in Universitas Papua. Email: harry_mat_unipa@yahoo.com  Toto Nusantara is Professor in Universitas Negeri Malang.  Subanji and Swasono Rahardjo is Lecturers in Universitas Negeri Malang