Comprehensive application course. Teaching material analysis Teaching Design of Mathematics in Bicycle: Comprehensive Application Course —— Mathematics in Bicycle is arranged after Unit 3 "Proportion" in the sixth volume of primary school mathematics in the experimental version of the curriculum standard. "Mathematical Problems in Bicycle" is a comprehensive practical activity class, which aims to let students solve practical problems by using the knowledge of circle, arrangement and combination, proportion and so on. To improve students' comprehensive use of what they have learned to discover, analyze and solve mathematical problems contained in life phenomena and feel the universality of mathematical application. For bicycles, students are familiar with them and have some life experience, but for the structural principle of bicycles, the changing relationship of gears and the basic principle of variable speed bicycles.