re: #169 Kenneth

That’s not very accurate.

100C x 2 = 200 + 30 = 230F (wrong answer)

100C x 2 =200 - 20 = 180 +32 = 212F (correct answer)

You are correct but as a rough rule of thumb x 2 +30 comes close enough espcially at more realistic temps, e.g., 20C by my calc becomes 70F while in actuality I think it’s 68F. Close enough for me to know whether I need a sweater or a parka…..
:)