I suppose it depends, McGrath, on what you regard as "real calculations". There was a time when I was required to deal with rods, poles and perches; groan! And then there was the business about calculating how many horses an electric motor was equivalent to, and whether the wiring and fuses would cope; more groan! And when it came to working out how to build a house that was energy efficient in a challenging climate? Triple groans!

Thank goodness I don't have to keep a shelf full of Ready Reckoners in my library or too many conversion factors in my head (although I can do a quick ready conversion between a few systems, in my head, still, and I happily converse with Americans to help them understand some of life's SI mysteries. Although they still insist that "metre" and "litrer" are, to quote Micro$ot's dictionary 'The English way of spelling "meter" and "liter", respectively'. I note that American surveyors have now standardised their units so that their versions of "Imperial Measures" (I've always wondered how Americans can bring themselves to use "Imperial" measurements) are all now exact multiples of the relevant SI metrications.

Cheers, Rowan