eng Science and Education Publishing American Journal of Educational Research 2327-6150 2015-10-17 3 10 1311 1314 10.12691/education-3-10-16 EDUCATION201531016 article Charita A. Luna charita_luna@yahoo.com 1 Emelia G. Aclan 2 Department of Mathematical Sciences, Mindanao University of Science and Technology, Lapasan, Cagayan de Oro City, Philippines Mathematics Supervisor, Division of Camiguin, Mambajao Camiguin, Philippines The study aimed to determine the subject matter knowledge (SMK) of Grade-V Mathematics teachers and the influence of teachers' Mathematics Pedagogy Content Knowledge (MPCK) training on their pupils' achievement. It used a quantitative and qualitative method of research to address the low performance of pupils in national and local assessments. The study was done in Camiguin among 40 teachers and 825 pupils who were randomly chosen. A teacher made test to assess the teachers' SMK and pupils' achievement with reliability of .95 and open-ended test to assess teachers' MPCK with reliability coefficient of .80. This test was given as pretest before teachers' training and posttest after training. Interview was done for triangulation. After analysis of the data the result revealed that the experimental group of teachers has significantly higher MPCK than those without training and pupils' achievement score is significantly higher than pupils under the teacher without training. The researchers recommend that teachers MPCK training be done to improve pupils achievement and teacher-training institutions should include MPCK in the curriculum. http://pubs.sciepub.com/education/3/10/16/education-3-10-16.pdf subject matter knowledge mathematics pedagogy content knowledge achievement