Before you get in a tizzy, don't worry. It looks hard, but it's not.
In the formulas below, / means to divide, * means to multiply, - means subtract, + means to add and = is equal. Tc = temperature in degrees Celsius, Tf = temperature in degrees Fahrenheit
To convert a Fahrenheit temperature into Celsius:
Tc = (5/9)*(Tf-32)
For example, to convert a Fahrenheit temperature of 98.6 degrees into degrees Celsius first subtract 32 from the Fahrenheit temperature to get 66.6. Then you multiply 66.6 by five-ninths to get 37 degrees Celsius.
To kind of do it in your head, imagine subtracting about 32 (make it an easy number close to 32 to subtract) ... then think of dividing THAT number in half. The real answer will be slightly higher.)
To convert a Celsius temperature into degrees Fahrenheit:
Tf = ((9/5)*Tc)+32
For example, to convert a Celsius temperature of 100 degrees into degrees Fahrenheit, first multiply the Celsius temperature reading by nine-fifths to get 180. Then add 32 to 180 and get 212 degrees Fahrenheit.
.... so, to get 450 degrees F into centigrade, you'd:
tC = (5/9)(450-32)
tC = (5/9) (418)
(now, just basically consider that you're multiplying by almost 1/2. if your answer isn't close to reasonable, check again. )
tC = 5*418/9
tC = 46.4 *5
tC = 232.2
If you tried it in your head, you'd have
1) subtract about 32 .... 450-30 = 420
2) divide into half ... 420/2 = 210
3) real answer is higher by less than 10% of 420 ... (42)
It's not dead on, but it gives an idea, anyway.
"In all our woods there is not a tree so hard to kill as the buckeye. The deepest girdling does not deaden it, and even after it is cut down and worked up into the side of a cabin it will send out young branches, denoting to all the world that Buckeyes are not easily conquered, and could with difficulty be destroyed." - Daniel Drake, 1833