Engelberg, K.J.K.J.Engelberg2022-03-082022-03-081995https://publica.fraunhofer.de/handle/publica/303157A number of preprogrammed tabular spreadsheets can be called up on the relatively large-surface and well-arranged display unit of a small portable desk-top calculator by means of corresponding function keys. The user can freely select the fields provided in the visual representation of the spreadsheets and enter numerical figures there. The calculation program then ensures that the mathematical relations linked to a specific problem are constantly maintained by automatically changing the values in all other cells after their input. The user has an overview of all the relevant parameters during all these processes and can thus follow the entire process of the calculation.de608patent1991-4127748