The last green dot on page 100 of the fifth grade math book is the knowledge point. Generally, each new lesson will have several green dots, that is, several knowledge points. Usually the first is the introduction of knowledge, the second is the third new lesson, and the fourth is the application of knowledge. The above introduction is for reference only! Draw five circles instead of the cake first, then divide each circle into four parts on average, and everyone gets a quarter of the cake. Five cakes are five quarters.