1. Determine the theme: Determine the theme of Unit 4, such as geometric figures or algebraic basis. Take the theme as the center of the mind map and write it in the center of a blank piece of paper.

2. List subheadings: List subheadings according to the content of Unit 4. For example, if the theme is geometry, subtopics can be listed as line segments, rays, lines, angles, triangles, quadrangles, etc.

3. Add details: For each sub-topic, you can add relevant details or important knowledge points. For example, under the subtopics of line segments, rays and lines, you can add their definitions, representations, attributes and other details.

4. Use colors and images: In order to make mind maps more vivid and easy to understand, you can draw with pens of different colors and add images and symbols. For example, themes and sub-themes can be emphasized with thick pens and pens of different colors, and important concepts or formulas can be represented by symbols or images.

5. Layout and structure: When drawing a mind map, pay attention to the layout and structure, and ensure that each theme and sub-theme has appropriate space and there is a clear connection between them. You can connect related topics and sub-topics with arrows or lines to show the relationship between them.

The application of mind mapping;

1, Learning Notes: In the process of learning, mind mapping can be used as a tool to take notes and help us better understand and remember knowledge. We can organize the knowledge points and concepts learned in class into mind maps to make them more organized and clear. Through the drawing of mind map, we can better understand the connection and hierarchical relationship between knowledge, so as to better master knowledge.

2. Project management: In project management, mind map can help us better organize and understand the various stages and tasks of the project. By decomposing the project into different modules and tasks, and expressing the relationship between them with arrows and lines, the progress and risks of the project can be better predicted, so as to better manage the project.

3. Meeting Minutes: In meetings, mind maps can help us to better record and organize the meeting contents. By arranging the agenda, speeches and discussion results of the meeting into a mind map, we can understand the progress and topics of the meeting more clearly, so as to better summarize the minutes of the meeting. At the same time, mind mapping can also help us find and solve problems better and improve the efficiency and quality of meetings.