When Robin Hayward asks “Metrication in 1972 – who remembers duo decimals and being unable to use a calculator to do maths now?”

(The Emperor’s new clothes, QS News, 30 September) – I can. The building industry went metric in 1968 with the publication of SMM5 (metric edition). I also remember that calculators were pretty thin on the ground in 1968, in fact non-existent. At that time we had desktop electro-mechanical calculators that were really just complicated adding machines. The first electronic calculators appeared in 1972 and were very expensive. But not for long as the high prices generated large profits causing lots of companies to jump into the market. Competition brought down prices and the end of the slide rule. (I still have one, perhaps I should offer it on ebay?)

Terry King, Dearle & Henderson

Source

QS News