F2C converts Fahrenheit to Celsius and vice versa
Fahrenheit to Celsius formulas http://www.manuelsweb.com/temp.htm
$ [sudo] gem install F2C
launch irb
require 'F2C'
Convert.F2C(value) #converts Fahrenheit to Celsius
Convert.C2F(value) #converts Celsius to Fahrenheit
$ irb
irb(main):001:0> require "F2C"
=> true
irb(main):002:0> Convert.F2C 100
=> "100 Fahrenheit is 38 Celsius"
