This research is examining the meaning of 'Developing Way'. Especally, in this paper, we consider it from the purpose of structuring the math. In conclusion, this meaning of mathematics to make students consider in 'Developing Way' is named to be 'Structured Development' which was classified into "Integration" "Generalization" and "Concise and Clear". Finally, we considered the teaching and learning processes of the topic of Area of a Sector from the structured development.