The simple point is to draw a square at the bottom of the paper, write down the strategy to solve the problem, and then draw two differentiated vertical lines, two squares above the vertical lines, one square to write two steps to solve the actual problem, the other square to write a picture to solve the actual problem, one square to write two steps to solve the actual problem, and then draw two differentiated vertical lines up and two squares above the vertical lines. One box writes out the combing relationship according to the problem analysis, and the other box writes out the equation. Write a square to solve the problem and then draw two differential vertical lines up. Draw two squares at the top of the vertical line. One square writes a line segment diagram according to the information and problems in the question, and the other square writes the known data to determine the unknown quantity and equivalence relationship.