A Precedent Drop-down list, like a dependent drop-down list, is a robust tool to incorporate in a best practice financial model, because it will restrict user inputs based on a previous drop-down list.
This follow-up article on the use of Excel AGGREGATE SUM introduces the added complexity of error cells, text cells or other erroneous cells that would cause errors with a standard Excel SUM function.
The simple SUM function is an adequate tool to aggregate a data array in a financial model. However there are some financial spreadsheets that will require a more robust Excel function, in order to provision for hidden rows, error values, and nested SUBTOTAL and AGGREGATE function cells.
The use of Excel AGGREGATE with SUM as the function syntax, depending on the Option selected, in terms of which values to disregard in the evaluation range for the function, will overcome certain problems with aggregating a data range.
The Excel Fill Handle can increase accuracy, efficiency and speed of a data input series across integer, date and other cell formats.