Celcius to Fahrenheit

"'ere Fred, how do you convert Centigrade to Fahrenheit?"

"Oh, it's easy, divide by 5, multiply by 9 and add 32."

"Thanks".

And that's how you end up with stories like this one in today's Daily Telegraph which ends:

The Arctic region has risen in temperature by 39.2F (4C) over recent decades according to scientists.

No, I really don't think they said 39.2°F, I think they just said 4°C and you converted it. Wrongly.

Oh, and yes, I did use "Centigrade" deliberately at the top of this posting.