Is that a lot, because we here donĀ“t use farenheit, we use celsius instead... :) Fahrenheit to Centigrade: C = (5/9) * (F - 32) 104 F = 40 C Centigrade to Fahrenheit: F = 32 + (9/5) * C Check out -40 for each of them. B) You can always derive these if you remember 0 C = 32 F and 100 C = 212 F, the freezing and boiling points of water. (Use the two-point formula for the equation of a line for the derivations.)