Russia was by no means entirely illiterate. Knowledge letters, invoices required in many sectors of business and other activities. Birchbark documents of Novgorod and other centers, a variety of written records (records, stories, etc.), writing on craft products (Coins, stamps, bells, arms, jewelry, art casting, etc.) suggests that educated people have never been translated in Russia, not only among the monks, but also artisans and merchants. Were they among the boyars and nobles. Wealthy people were written record of their farms, from the XVI century. survived various accounting books, documents, spiritual abodes – monasteries, copies of the documents of earlier times. Available scientists, despite the loss of Batu era and later, the Horde "ratey", there is still a lot of handwritten material in XIV-XVI centuries. This – the documents (the spiritual letters, contracts greats, including Moscow, and the princes, economic acts Russian metropolis, episcopal, monasteries), lives of saints, chronicles, and many others.
There are other guidelines for grammar, arithmetic, herbal therapy (Azbukovnik, herbalists, etc.). Accumulated practical observations, knowledge of construction equipment (were needed in the construction of buildings), dynamics (calculated flight range of stones, the nuclei of battering and other devices, from guns, which appeared in the late XIV century.) Applied Physics (coinage, casting cannon, assembly and repair of mechanical movement), Applied Chemistry (manufacture of paints, inks), arithmetic and geometry (description of land dealings, etc.). Descriptions of natural phenomena (Eclipses, earthquakes, etc.) are frequent in the chronicles. Translations were popular works – "Christian topography" of Cosmas Indicopleustes (traveler VI.) "Six Days" John, the Exarch of Bulgarian, "Gromnik" and other astronomical observations are given in Russian manuscript collections, medical – in the same annals (description of illness).