Sir – A reader recently pointed out some examples of erroneous mathematics when an increased figure was described as ‘times’ the previous amount rather than ‘more than’. Another area in which poor maths is prevalent is that of comparing temperatures. During an earlier warm spell this year, one of the weather forecasters on BBC Oxford television said that it had been “14 degrees — double what it should be for the time of the year” (ie 7C). That would be true only if zero Celsius were absolute zero, which of course it is not. Absolute zero is -273.15 degrees Celsius, or 0 on the Kelvin scale. Thus twice 7C (280.15 K) would be 560.3 K — a searing 287.15 Celsius. Phew — what a scorcher! Similarly, our own Bishop John described the 1,200 degree burning coals over which he bravely walked for charity as being “six times hotter than your oven” (meaning, one assumes, 200 degrees). But the coals, at about 1,470K would be only three times an average oven temperature of 470 K.

Bishop John is a charming man, whose theology may be impeccable, but on this occasion, his maths is not!

Rick Taylor, Eynsham