#{:
(,"Fahrenheit","Celsius"),
("boiling point",212^@F,100^@C),
("freezing point",32^@F,0^@C),
("difference", 180F^@,100C^@)
:}#
So
#color(white)("XXX")180 F^@=100C^@#
#color(white)("XXX")1F^@=100/180C^@#
#50^@F#
#color(white)("XXX")# is #50^@F-32^@F#
#color(white)("XXXX")=18F^@# above freezing.
#18F^@ = 18xx100/180C^@=10C^@#
#10C^@# above freezing is #10^@C#