ISBN, also known as ISBN, is the abbreviation of English ISBN. ISBN consists of four * * * ten digits. The first paragraph is the group number, which is the code of a country, region, language or other organization, and is assigned by the International Book Number Center. China's group number is the number "7"; The second paragraph is the publishing house number, which is assigned by the National Standard Book Number Center. The number of digits varies according to the number of books published by the applicant publishing house. The press number of Shandong People's Publishing House is "209"; The third paragraph is the book serial number, which is managed and distributed by the publishing house; The fourth paragraph is the check code, and its value is calculated by the weighted sum of the first nine bits from 10 to 1, taking1as the module.