FWIW...
Me and the GF were in bed one night, and for a reason that escapes me, we wanted to do a temperature conversion.
She knew that 32F is the freezing point of water, I knew that -40 is -40 on either scale. Which is enough information to work it all out.
Did the math in our heads, got an answer.
Decided to check it, picked my cell phone up, hit the menu button, hiut "Extras", and there, right below where it said "Calculator", it said "Convertor",
So, if you have a Nokia cell phone it may well have a conversion function built in. does weight, length, area, and volume too, as well as some you can programme yourself apparently.
We'd got it right if you were wondering....