ISBN number consists of 10 digits, and * * * is divided into four parts:
1. Group number: represents the country, geographical region and language of the publisher. China's group number is "7".
2. Publisher number: represents a specific publisher (publishing house, publishing company, etc.). ) belongs to the group. Set and assigned by the ISBN center of a country or region, 1-7 digits.
3. Title: The title is the number given to each publication by the publisher.
4. Inspection number: the inspection number is the last digit of the ISBN number. You can check whether the ISBN number is correct, that is, multiply the number of ISBN 1-9 by the nine digits of 10-2, and add the inspection number to the sum of these products. If it can be divisible by 1 1, the ISBN number will be. The check number can only be 1 digit, and when it is 10, it is recorded as Roman numeral X.