Late medieval astronomical manuscripts produced in Europe attest to different kinds of historical practices. Computations are one such practice and the focus of this contribution. My hypothesis is that a detailed analysis of the manuscripts and a deep understanding of what computation was for late medieval astrologers or astronomers in Europe are mutually beneficial. By concentrating on one of the manuscripts associated with the late fifteen-century astrologer Conrad Heingarter, I show that the document has specific characteristics of a slowly assembled personal toolbox for computation. I also argue that the multigraphic properties of the document are fundamental to understanding calculations that values comparing multiple computation paths among astronomical quantities.