The difference between the second edition of the third grade mathematics book in primary school and the 2022 edition is that the content and knowledge points are different and the teaching resources are different.

1. Different contents and knowledge points: With the continuous advancement of education and teaching reform, the contents and knowledge points of teaching materials will be adjusted and updated. Compared with the previous version, the 2022 version will involve the adjustment and update of some knowledge points, and add new teaching concepts and methods.

2. Different teaching resources: 2022 textbooks will be equipped with more teaching resources, such as supporting teaching videos, teaching software, courseware, etc., to enrich the teaching content and improve the teaching effect.