The present paper explores the shaping of mathematical thought within Eastern and Western manuscript cultures. It provides a comparative, corpus-based cross-linguistic analysis which covers a period of approximately 600 years (800 CE‒1400 CE) and examines mathematical manuscripts written in Sanskrit, Arabic, Byzantine Greek, medieval Latin, and Italo-Romance dialects. By drawing on multiple perspectives and several academic fields, I investigate a selection of highly representative mathematical manuscripts in order to better understand the production and consumption of mathematical knowledge, mathematical pedagogy, reading cultures, writing practices, the use of mathematical riddles as a learning technique, and identify knowledge exchange across space and time. The history of mathematical thought is, in fact, a history not only of texts but of texts within their contexts, not only of writings but also of the intellectual, social, and institutional settings that called them forth. This study also explores dynamics of cross-linguistic contact and circulation of ideas from India through the Mediterranean world which paved the way for the transmission, adoption, and adaptation process of Indo-Arabic numerals and positional numeration. This paper pushes disciplinary boundaries by combining methodological approaches and juxtaposing mathematical cultures which are too often discussed in isolation from each other.