Once upon a time tax computations were prepared by hand. In my firm the assistant would be surrounded by audit files and add the details needed onto 14-column yellow paper. There would then be a complicated process to review the computation; reference all the numbers and check it all added up before handing over the computation to a typist. Finally the typed version would be referenced again. There was a real art to preparing the computation; the core skill was to provide sufficient clear details to minimise the volume of enquiries raised by the Inland Revenue.
The next step was the massively dangerous one of preparing computations on spread-sheets. This was a timesaver since the computer could do the calculations and corrections could be processed easily; the danger arose from the fact that the preparer and reviewer often got the formulae wrong and the machine...
