This book includes a research study that suggests that both students' graphical and algebraic thinking need to be utilized and integrated in order to construct a deep mathematical understanding of the concepts. Traditionally, algebraic and graphical thinking are considered as two separate thought processes as well as different learning styles in mathematic curricula. Thus, curriculum developers and textbook authors provided graphical and algebraic tools separately to support a person's related learning styles. The study in the book revealed that this traditional perspective may cause obstacles, even to honor students. Therefore, the pedagogical approach in new curricular or mathematics textbooks can focus on the interrelation and complementary aspect of algebraic and graphical thinking in an ongoing back-and-forth process in learning quadratic functions. There is a need to continuously relate algebraic thinking with graphical strategies and graphical thinking with algebraic strategies for any particular concept. This book is addressed to researchers in mathematics education as well as teacher education involving both prospective and in-service teachers.