How to code books in kindergarten, the simplest is as follows. Every grid that can hold books has a number. If there are six squares in the book, from 00 1 to 006. The books in each grid are coded. For example, a grid can hold 80 books, ranging from 00 1 to 080. The grid code+book number is a complete code. For example, the code 005023 indicates the 23rd book in the 5th box. Whoever gets the book will know immediately which box to put it in. In fact, there are not many books in a grid in the library. The serial number is only used to distinguish the only book, and it does not need to be discharged according to the serial number. Put it in the right grid.