The books in this series aim to help primary school students practice spelling, alphabetical sorting, and dictionary usage. The young students copy many times in these books and learn spelling and the basic vocabulary of each school subject, as well as supplementary words and sentences composed of selected, familiar letters to the child.

The Index is particularly useful as children practice correct writing and alphabetical sorting of new words they learn or those that present spelling difficulties.

It is a small dictionary that the student is called to create themselves, and this is particularly important for them because it gives them the joy of creation and self-motivation.