Centigrade degrees into Fahrenheit: multiply by 9, divide the product by
5 and add 32.
Fahrenheit degrees into Centigrade: subtract 32, multiply by 5, and
divide by 9.
Reaumur degrees into Fahrenheit: multiply by 9, divide by 4, and add 32.
Fahrenheit degrees into Reaumur: subtract 32, multiply by 4, and divide
by 9.
Reaumur degrees into Centigrade: multiply by 5 and divide by 4.
Centigrade degrees into Reaumur: multiply by 4 and divide by 5.