Just because it keeps coming up, here's a little Celsius-Fahrenheit conversion primer:

To get from Celsius to Fahrenheit, subtract 10%, multiply by two and add 32. Example: 20C. Taking 10% off gives 18, doubling gives 36, adding 32 gives 68F.

To get from Fahrenheit to Celsius just reverse the above. So you subtract 32, divide by two and add 10%. To be precise, you'd have to add 11.11111(and so on) percent, but 10 is close enough. Example: 100F. Subtracting 32 leaves 68, dividing by two give 34, adding 10% gives 37.4, whereas the precise value is 37.777777(and so on).

These days I actually find it easier to memorize some values and go from there. Ten degrees Celsius difference correspond to 18 degree Fahrenheit difference. So once you remember that 0C is 32F, you can make a little table.

C   F
 0  32
10  50
20  68
30  84
40 104
50 122

Just memorize the one that's closest to home and off you go. Ten more degrees in C means 18 more in F, and 5 more in C means 9 more in F. So 25C is 77F and 27C is roughly 81F because in between the 5C steps using 2 as the factor is close enough.

I guess I may be overthinking certain things. :biggrin:

-- I'm not mad at you, just Westphalian.