Presently, many practitioners, researchers and educators have given deep attention to the development and enhancement of teaching mathematics and mathematics education world-wide. Yet, many problems still exist when we are looking to the classroom and see how math teachers do their job. Teaching mathematics is always being a challenging issue to be explored, and there is no easy-single recipe for helping all the teachers to become effective and professional. In this essay, however, I try to make a very brief explanation on how teachers should teach mathematics by considering theory and several aspects of teaching mathematics in the classroom.

In order to answer this question, I propose three premises underpin what the idea I want to explain. Firstly, I argue that teachers as professional ones have to understand well about the contents of mathematics, the development of the students and pedagogical aspects of mathematics. Teachers have to know deeply about the topics that s/he is going to teach and be able to formulate the knowledge with meaningful contexts in their teaching approach. Effective mathematics teaching requires creativity and flexibility of the teachers to propose certain questions that can help the students to think. The teachers also have to understand the strength and weakness of the learners. They have to know the development of students’ understanding of mathematics and what kind of help that s/he can offer in order to guide the learners and prevent them from misunderstandings. Moreover, the teachers also need to understand the big ideas, strategies and models involving in the certain topics of mathematics. By having these kinds of things in mind, the teachers will be able to select and use appropriate tools and materials that can engage the students to develop their mathematical understanding.