Students in Hong Kong, an urban city in China, have consistently reported good mathematics performance in international comparative studies. The city, like other parts of China, shares a classroom culture that expects students to pay a very high respect for the teachers. The teacher in turn takes a very important leading role in the classroom orchestrating the various events in the class. What does a competent teacher do in a mathematics lesson? What pedagogical philosophy does the teacher have? How does the teacher help the students to develop an understanding of the school subject? This paper reports a case study of the teaching of algebraic equations by a competent teacher developed from the data of the Learner’s Perspective Study, attempting to provide answers for some of these questions. The design of the study provided the possibility of the juxtaposition of the researcher’s analysis of the lesson with the teacher and students’ perspectives on the lesson. Findings show that the details and complexity of the subject matter unfolded in the teacher’s systematic planning and teaching form a powerful way to direct the students to see the mathematics in a certain way.