International standard symbols are marked with "ISBN" followed by the number 10. The number of this 10 is divided into four parts, namely, group number, publication number, book number and inspection number, separated by "-"or spaces. "7" is the group number, representing the number of a country, region or language, and 7 refers to China. "107" refers to the number of the publishing house, which can be as many as 7 digits. This 107 refers to the number of People's Education Publishing House. "186 17" is the serial number of the book, that is, the number of each publication of the publishing house, and "6" is the check code.