Teacher belief is a well-researched area in the international literature. Evidence shows that teacher practice is deeply influenced by the relevant beliefs they hold. This book reflects the findings from an empirical study that focuses on teacher beliefs regarding mathematics related topics and practices. Extensive literature has constituted the theoretical framework for the study. It was conducted on secondary mathematics teachers of Bangladesh using both quantitative and qualitative techniques. Mathematics teachers hold multiple and conflicting views. Simultaneously they confirm their association with instrumentalist, Platonist and constructivist views of mathematics emphasizing both teacher- and student-centered approach for learning. This suggests that teachers may be in between an alteration process of their beliefs that results in holding multifarious contending views. The book contents include background knowledge, significance of studying teacher beliefs, literature review, study approach, findings and implications. Education researchers, policy makers, students and professional development providers will be benefited from the content of the book.