School is compulsory in China for from 1st to 9th grade. After 9th grade, students must take an exam to enter the next phase of education; senior high school (a college track), vocational, specialized, or craft. After graduation from senior high school, students can take the Huikao (college entrance exam) and be accepted into a college or university. The competition for acceptance to these institutes of higher learning is fierce and Chinese students learn early on that education is synonymous with success. Twenty five percent of the entrance exam into college is mathematics, so there is much emphasis placed on math in the Chinese education system.
(Source: Center on International Education Benchmarking: http://www.ncee.org/programs-affiliates/center-on-international-education-benchmarking/top-performing-countries. 2012. Washington D.C.)