The metric system is not only great, it's also used in science without exception. Science includes biology, which includes zoology, which means animals and stuff. Stuff related to zoos.
Without malignancy and with all available toungs-in-cheek: "Welcome to the modern world!"
Just remember that at or below 0° Celsius water starts to freeze (It`s based on that). And around 20° would be mild summer, at 30° its already pretty hot and at 40° it starts to get serious.
But i hope that you imperials (is it called imperial?) get an easy solution for this.
However most of my 'troubles' come when I try to convert meters to feet/yards and kg to pounds and km to miles.
An inch is 25mm
A mm is 40thou
A meter is not far from a yard or 3' (3'=0.9m actually - slightly less roughly)
a kg is 2.2lbs
A mile is 1.6 km
And these days google can translate - just search '1gallon litres' and then get really confused if you live in the UK where you expect 1 gallon = ~6 litres (we have man sized gallons here )
-40 degrees is the point where Celsius and Fahrenheit meet.
Well, when you have 0 degrees Celsius it is also 32 degrees Fahrenheit. There are 1.8 degrees Fahrenheit to 1 degree Celsius. 40 times 1.8 equals 72. This means that, when you are at -40 Celsius you are also at -40 Fahrenheit.