In the two decades hand-held calculators have been readily available, there has been ample time to develop a usable design and to educate the consumer public into choosing quality devices. This article reviews a representative calculator that is &&state of the art'' and shows it has an execrable design. The design is shown to be confusing and essentially non-mathematical. Substantial evidence is presented that illustrates the inadequate documentation, bad implementation, feature interaction, and feature incoherence. These problems are shown to be typical of calculators generally. Despite the domain (arithmetic) being well de"ned, the design problems are profound, widespread, confusing*and needless. Worrying questions are begged: about design quality control, about consumer behaviour, and about the role of education*both at school level (training children to acquiesce to bad design) and at university level (training professionals to design unusable products). The article concludes with recommendations.
&&The problem of e$cient and uniform notations is perhaps the most serious one facing the mathematical public.' ' Florian Cajori (1993) &&[. . .] contrivances adapted to peculiar purposes [. . .] and what is worse than all, a profusion of notations (when we regard the whole science) which threaten, if not duly corrected, to multiply our di$culties instead of promoting our progress. '' Charles Babbage, quoted in Cajori (1993).