Integration of Products using Differentials Rebecca C. Tolentino 1 and Janette C. Lagos 2 1 rctolentino@plm.edu.ph 2 jkimwin@yahoo.com Pamantasan ng Lungsod ng Maynila (University of the City of Manila) Philippines Abstract: This paper is an attempt to increase students’ performance in Integral Calculus by the inclusion in the curriculum of a new integration technique, Integration of Products using Differentials, introduced by Dr. Tilak de Alwis. The study was conducted in the only locally funded chartered university in the Philippines. The study employed mixed method research design where students performance and verbal feedbacks were analyzed. Results showed a ratio of 2:3 attempts versus no attempts. Findings showed that the performance of students who attempted to use the technique is not significantly different from the performance of students who did not attempt to use the technique. Among the attempts group, success rate is higher in items involving integration of products than their over-all success rate while for the no-attempts group success rate is not significantly different. I. Introduction According to the National Council of Teachers of Mathematics [1], a strong foundation in mathematics is increasingly important in almost all fields of study most especially in arts, physical sciences, engineering and, health sciences. Mathematics has become important tools for analysis and interpretation of the data they dealt with and, validation of the contrivances that they had produced. Singapore Ministry of Education characterized mathematics as an excellent vehicle for the development and improvement of a person’s intellectual competencies. In the job market for instance, as cited by US Department of Education Mathematics Equals Opportunity [2] workers who have strong mathematics and science backgrounds are more likely to be employed and generally earn more than workers with lower achievement. It is for this reason why performances of students in mathematics and science are measured regularly. Trends in International Mathematics and Science Study (TIMSS) for instance, annually reports performances of students worldwide in the two mentioned subjects. For the past 20 years, TIMSS has measured trends in mathematics and science achievement at the fourth and eighth grades. It has been conducted on a regular 4-year cycle since 1995, making TIMSS 2011 the fifth assessment of mathematics and science achievement trends. TIMSS Advanced measures trends in advanced mathematics and physics for students in their final year of secondary school. Results of the TIMSS assessment have become a reference of all nations in developing their mathematics and science curriculum. Carbello [3], reported that the Science and Education Institute study on Trends in Mathematics and Science Study in 2003 showed that Philippines’ 8th grade (2nd year high school) students’ skills and competencies in Math ranked a pitiful 42nd out of 46 participating countries while the Philippine 4th grade students placed 23rd out of 25 participating countries. This report is quite alarming because if this trend continues poor performance in mathematics in the tertiary level is expected. In the study of Salleh and Zakaria [4], they raised concerns about the decline in student’s performance in Integral Calculus. In this subject integration is an important concept in