This work by Theon of Smyrna is extensively referenced by historians of mathematics because it provides much information about the arithmetic of the Pythagoreans, as well as music and astronomy from various periods of ancient Greece.

The work is divided into four sections: "Introduction," "Arithmetic," "Music," and "Astronomy." In the first section, the usefulness of mathematics is discussed. In "Arithmetic," there is a clear reference to Pythagorean arithmetic. In "Music," almost all elements of the theory as they had developed up to the time of Theon are presented. Finally, in "Astronomy," a summary of almost all views of ancient Greek astronomers regarding the science of the heavens is outlined.

It is a fact that some topics of the work are addressed briefly. However, we must not forget the purpose of writing the work, which is the preparation of those who wish to study the Platonic dialogues. The fact that it does not delve deeply into Platonic questions in mathematics and astronomy does not contradict the purpose of the work stated in its title.