1. Preparation tools: Prepare hand-drawn paper and pen. Alternatively, you can choose to use online tools, such as XMind, MindMaster, etc.

2. Determine the central theme: determine the names or themes of the four units and write them in the center of paper or editing tools. For example, the theme of Unit 4 is "Fraction". You can write "Fraction" in the center of the paper or on the editing tool.

3. List subtopics: List subtopics related to the central theme. For example, the topic of "Fraction" can be listed as subtopics such as "Definition of Fraction", "Nature of Fraction" and "Addition and subtraction of Fraction".

4. Add details: For each sub-topic, add more details and points. For example, the subtitle "Definition of Fraction" may include "What is the definition of Fraction?" And "how to read music?" Waiting for details.

5. Draw connecting lines: connect various topics and sub-topics with arrows or lines to show their relationship. For example, you can draw a line under "Definition of Fraction" and then write "Nature of Fraction" on the other side of the line to show the relationship between these two topics.

6. Improve the graphics: check and modify the mind map to ensure that the contents of the four units are clearly and intuitively reflected. For example, you can adjust the positions of various topics and subheadings to make them more logical.

Matters needing attention in drawing mathematical mind map;

1. Use concise graphics: In the mathematical mind map, concise graphics and symbols should be used to express concepts and relationships. For example, you can use arrows to represent functional relationships, boxes to represent definitions or theorems, and circles or ellipses to represent concepts or problems.

2. Pay attention to the hierarchical structure: in the mathematical mind map, pay attention to the hierarchical structure, that is, the depth and breadth of concepts or problems. When painting, you should put the theme on the top layer, and then expand the layers according to the theme content. Each layer is distinguished by different sizes and colors of graphics or symbols.

3. Highlight the key points: In the mathematical mind map, we should highlight the key points and difficulties. For important content, you can use larger or thicker fonts, colors or graphics to emphasize, and for difficult content, you can use notes or explanations to explain and explain.

4. Pay attention to color matching: color matching is also an aspect that needs attention in mathematical mind mapping. Different colors can express different concepts and relationships, making the whole mind map more vivid and interesting. At the same time, color can also help memory and understanding.

5, keep clear and easy to read: when completing the mathematical mind map, you need to pay attention to keep clear and easy to read. Each figure or symbol should be clearly marked, and the distance between different levels should be appropriate, which is convenient for readers to understand and remember the whole mathematical knowledge structure.