High school math league is divided into AB two sets of papers. Generally, paper A is more difficult and paper B is easier. Volume b focuses on the investigation of computing power, while the investigation of thinking is slightly lower.
Zhejiang, Jiangsu, Hebei, Hunan, Hubei, Beijing, Shanghai, Guangdong and other provinces use Volume A; Volume B is used in Inner Mongolia, Guizhou, Ningxia, Xinjiang and other ethnic minority areas.