Maximos Planoudes on numbers

Around 1300 Maximos Planoudes composed his treatise The So-called Great Calculation according to the Indians, in which he suggested the use of the Indian (i.e. Arabic) numerals in arithmetic and introduced the use of zero. Maximos Planoudes had studied the treatise «Great Calculation according to the Indians», written in 1252 by an unknown author, which he had borrowed by George Bekkos, as is gathered from the following extract of a letter of his.

Ἐμοὶ δὲ καὶ ταυτὶ μὲν γράφεται· τὸ δὲ πλέον ἑκάστης ἡμέρας, ἐξ οὗ τὴν βίβλον ἣν ἴστε παρ’ ὑμῶν ἐχρησάμην, ὁ κατ’ Ἰνδοὺς ἀριθμὸς δαπανᾷ καὶ θεοῦ διδόντος ἤδη τὸ πᾶν ἤνυσται. καί με οὐδὲν διέδρα τῶν ἐν αὐτῷ, πλὴν καὶ ταῦτα προσθεῖναι τῇ γραφομένῃ μοι βούλομαι βίβλῳ· πῶς, οὑτινοσοῦν ἀριθμοῦ δοθέντος μὴ τετραγώνου, τὸν ἔγγιστα τούτου δυνατὸν εὑρεθῆναι τετράγωνον; καὶ ἔτι· πῶς, οὑτινοσοῦν ἀριθμοῦ τετραγώνου δοθέντος, τὴν αὐτοῦ πλευρὰν εὑρεῖν οἷόν τ’ ἂν γένηται; εἰ δὴ ταῦτα τῶν ὑμετέρων που βιβλίων ἐντέτακται ἢ καὶ ἄλλως ἔστιν ὑμᾶς εἰδέναι, εὐκταῖα ἂν ἐμοὶ δράσαιτε, εἰ γράψαντες πέμψαιτε.

Maximos Planoudis, Letters, 46.35-45, ed. P. L. M. Leone, Maximi Monachi Planudis Epistulae (Classical and Byzantine Monographs 18, Amsterdam 1991).