We know for sure that Ancient Greek mathematics was known to the Romans. The second oldest copy of Elements that we have is the version edited by Theon of Alexandria, who lived from c. 335 - c. 405 CE. Theon was a mathematician and mathematics teacher who lived in Alexandria and may have been one of the last members of a prestigious educational institution known as the Museum [1]. The works of Greek mathematicians formed a fundamental part of the curriculum that Theon taught.

Theon’s edits typically went beyond corrections and minor typographical notes. In his edition of Elements, he explicitly wrote that his aim was to improve Elements from a pedagogical point of view by correcting typos and errors, making the writing style more consistent, and expanding proofs that his students would find cryptic. According to the historian Heath [2],

... while making only inconsiderable additions to the content of the "Elements", he endeavoured to remove difficulties that might be felt by learners in studying the book, as a modern editor might do in editing a classical text-book for use in schools; and there is no doubt that his edition was approved by his pupils at Alexandria for whom it was written, as well as by later Greeks who used it almost exclusively...

We also have copies or partial copies of other works Theon edited, including Euclid’s Optics, and Data, and Ptolemy’s Almagest, Handy Tables, and Synaxis. These editions appear to be written at a variety of different levels, and historians believe that they were designed for students of different proficiencies.

There is little surviving original work by Theon, and J. J. O’Connor and E. F. Robertson (1993) describe him as “a competent but unoriginal mathematician.” He may have written a book called Calotropica, as though the work lists Euclid as the author it incorporates ideas not believed to be known in Euclid’s time. Byzantine and Arabic sources refer to other original writings of Theon, including Treatise on the Astrolabe and On the Rising of the Dog[-Star]. This apparent interest in astronomy matches records of Theon correctly predicting eclipses.

Theon’s daughter was Hypatia, the first known woman mathematician in the West. Some of his works co-credit her, such as the note in Book III of Almagest that states “the edition having been prepared by the philosopher, my daughter Hypatia.” Hypatia, in her own right, wrote commentaries on Diophantus's Arithemtica (a 13-volume tome that gave birth to several fields of modern mathematics research) and on Apollonius’s writings on conic sections. Wilbur Knorr suggests that she also edited Archimedes’ Measurement of a Circle, a work that contained a significant amount of information about π [4]. According to Catherine Castner (2010), the ability to write intelligent commentaries on Apollonius‘ writings on conic sections and Archimedes’ Measurement of a Circle indicates that Hypatia was among the most component mathematicians of her time.

Hypatia was also known for building astrolabes and hydroscopes, the later being an ancient device for measuring the density of liquids. The construction of these devices required detailed knowledge of Greek research on geometry and physics.

[1] He is described as a member of the Museum by a source writing in the 10th century. Although we are not sure when the Museum closed, it definitely ceased to exist during Theon’s lifetime. J. J. O'Connor and E. F. Robertson (1993) conclude that “[o]n balance it seems reasonable to accept that he was one of its last members.”

[2] T. L. Heath, “A History of Greek Mathematics,” 1921.

[3] Copies of this work are believed to have been edited by Theon, though they do not credit him.

[4] Only a fragment of this work survives, however it is referenced by later writings in ways that suggest it is rather extensive. One of the surviving propositions states

The ratio of the circumference of any circle to its diameter is greater than 3 + 10/17 but less than 3 + 1/7.