A variety of medical procedures require arithmetic calculations to be performed. These calculations can be complex and induce errors that can have serious consequences on the ward. In this paper, we consider whether a graphical representation might make these calculations easier. The results of a laboratory experiment are reported in which participants were asked to solve a number of infusion parameter problems that were represented either graphically or textually. Results show that participants were faster but no more accurate in solving graphical problems than they were textual problems. We discuss the need for situated work to be conducted that builds on these initial findings to determine whether the advantages of graphical representations transfer to actual workplace settings.