The invention relates to a computer-implemented method for displaying data values calculated by a spreadsheet-function, the method comprising: Specifying one or more formal output parameters by specifying, for each formal output parameter, a first cell of a spreadsheet document, Specifying one or more formal input parameters by specifying, for each formal input parameter, a second cell, Specifying a spreadsheet-function body, wherein the specified spreadsheet-function in operation provides a user with the option for: Calculating a first output parameter value, Displaying the one or more first output parameter values or a data value having been derived thereof in a 3rd cell, Calculating a second output parameter value, and Displaying the one or more second output parameter values or a data value having been derived thereof in a 4th cell, wherein the 3rd cell and the 4th cell display their respective data content within the spreadsheet document at the same time.