Asia Pacific Journal of Education, Arts and Sciences, Vol. 4 No. 3, July 2017 ______________________________________________________________________________________________________________ 108 P-ISSN 2362-8022 | E-ISSN 2362-8030 | www.apjeas.apjmr.com Effectiveness of Multilingual Teaching of Mathematics in a Tertiary Level State University in Bicol Region, Philippines Eden C. Paz (PhD) Central Bicol State University of Agriculture, San Jose Pili, Camarines Sur, Philippines edencpaz@yahoo.com Date Received: June 21, 2017; Date Revised: July 25, 2017 Asia Pacific Journal of Education, Arts and Sciences Vol. 4 No.3, 108-113 July 2017 P-ISSN 2362-8022 E-ISSN 2362-8030 www.apjeas.apjmr.com Abstract - Multilingual instruction is essential in alleviating students’ performance. Hence, this study recognizes its importance in the teaching-learning process in Mathematics especially in plane and solid Geometry among college students. Its focus is on the use of English, Filipino, Bikol and other local dialects within the Bicol region as media of instruction. Quasi- experimental method was employed using the two- group post designs. The teacher-made pre-and-post- tests were utilized to assess the students’ performance in the two mathematics classes which are handled by the researcher and became the subject of the study. One class was the control group using English alone as medium of instruction, while in the experimental class it employs multi-lingual instruction. Said classes were comparable because of an almost equal mean scores obtained in the pre-test. Convenient non- random sampling technique was used to determine the sample classes and simple average to determine the scores of both pre- and post-tests. T-test analysis was used to determine the significant difference between students’ performance in the two classes. Result of the study revealed significant difference in the students’ performance between the two groups. A homogeneous students’ performance in the experimental group was observed as evidenced by a practically the same high scores obtained by the students in the post test. It therefore implies that the use of multilingual instruction in mathematics significantly contributed to the performance of the students. Keywords: Multilingual instruction, language, dialects, quasi-experimental method, students‟ performance INTRODUCTION The Philippines is an archipelago composed of more than 7,000 islands. It is a typical example of a multilingual state because of its diverse languages and local dialects such as Bikol, Ilokano, Cebuano, etc. There are more than 170 languages around the country [1]. In the Bicol region there are four groups of Bikol dialects spoken, namely: Bicol Naga, Bikol Rinconada, Bikol Albay and Bicol Catanduanon. Although, Bikol Naga dialect is spoken all over the region, there are still other dialects used in addition to Filipino and English. While it is a mandate to use vernacular in the lower levels of the K to 12 programs, it is inaudible in the higher education level because English is the medium of instruction adopted. The use of bilingual or even multilingual instructions is true elsewhere. Multilingual instruction has been considered a reality for decades. It conveys the ability of societies, institutions, groups, and individuals to have regular use of more than one language in their everyday lives over space and time, while language is impartially understood as a variety that a group admits to using as a habitual communication code [2]. In effect, from multilingual instruction in classroom to multilingual communication in institutions or organizations, allows opportunities for the employee-employer team work in the pursuit of their individual-organizational goals. Both will be equipped with appropriate adjustments. According to one researcher, the organization‟s perspective concerns the question of how the presence of or demand for multiple languages in the company is managed. And also how companies are guided by national and other policies in regard to the use of multiple languages and at the same time, how they create their own internal policies while the individual perspective examines the ways in which the presence of multiple languages is managed by the employees [3]. In Mathematics, medium of instruction plays a significant role in the teaching-learning process. In the Philippines, mathematics is being taught in English