教材与学情分析综合应用“自行车里的数学”是在第三单元“比例”之后安排的。旨在让学生运用所学的圆、排列组合、比例等知识解决实际问题。“自行车里的数学”主要研究两个问题:普通自行车的速度与其内在结构的关 Teaching materials and analysis of the comprehensive application of knowledge “Math in bicycle ” is arranged after the third unit “ratio ”. Designed to allow students to use the circle learned, arranged in combination, the proportion of knowledge to solve practical problems. “Math in Bicycles ” focuses on two issues: the speed of an ordinary bike and its inherent structure