It is worth setting your calculations out as a series of simple calculations rather than trying to do everything in one huge cell formula - it makes them much easier to read and even easier to check for errors. This area displays the results. It is sometimes convenient to place the input and the output areas next to each other so that you can see the effect on the output of changing a parameter in the input. Macros Area Complex spreadsheets may have a set of macros attached to them which are saved on the spreadsheet along with everything else. You will need an area in which to store them, as well as space to annotate the macros with comments explaining what they do.
Documentation is especially important here as most macro languages are difficult to read.
First a few general rules about spreadsheet design. A spreadsheet normally looks the same no matter what area of it you are looking at, so it is important that you know where all your data is and how you can navigate your way to it easily. For this it is useful to sketch out your design on a piece of A4 graph paper. Divide the paper up into sections, label each section as to what it contains and give the cell references that delimit the areas on the spreadsheet. Due to the unexciting nature of spreadsheet interfaces, in reality there are only really three major design ideas that you can employ, namely block design, linear design and multisheet design .