NEP 2020 emphasizes constructivism. If you want to study and teach, first you should know the concept, principles and assumptions of Constructivism. Knowledge of how to use Constructivism is essential. A teacher must also know how Constructivism is used in various subjects. A number of epistemological approaches can be used in the study and teaching of mathematics and they can be classified into three categories. 1) Student-centered 2) Teacher-centered 3) Student-teacher cooperative teaching methods Teaching techniques and teaching paradigms are used to formulate the curriculum. It is implemented considering the prior knowledge of the student. That is, mathematics is a subject of understanding and living. Students study will not be meaningful without changing the role of teacher to teach and student to study only.