In many places, the ninth grade mathematics uses the textbook of People's Education Edition. For example, nationwide, Hebei, Henan, Shanxi, Guangxi Zhuang Autonomous Region, Jilin, Heilongjiang, Yunnan, Guizhou, Gansu, Qinghai, Inner Mongolia Autonomous Region, Xizang Autonomous Region and other provinces all use PEP textbooks.

In other words, in the third grade, the People's Education Edition was used. Textbooks are mainly published by People's Education Edition, such as Shanghai Science Edition, Guangdong Education Edition, New Curriculum Standard, People's Education Edition, Guangdong Education Edition, Jiangsu Science and Technology Edition, Beijing Normal University Edition, etc. The most mainstream ones are Beijing Normal University Edition and People's Education Edition, and then the rest are applied to a few areas, so the application fields of People's Education Edition are relatively wide.

So the ninth grade math is the place shown above.