Wait, so it's just "five Kelvin", not "five degrees Kelvin"? TIL.
Now that I think about, what's the etymological reason we use "degrees" to talk about temperature? We don't measure force in "degrees Newton" or electric current in "degrees Ampère". Why do we do it for Celsius and Fahrenheit?
Five kelvins. Just like five metres, no capital letters or funny symbols.
The reason you can do it for Celsius or Fahrenheit is that those are scales but not units. The energy in two bodies (with constant heat capacity) at 100° is not the same as in a single body at 200°, but if you use kelvins then it works out.
Kelvin is the standard unit for temperature, 0 Kelvin is the absolute zero point. Each step is the same size as a degree Celsius, but there are no "degrees".
Edit: remove assertion that the scale does not go into negative, because physics.
As a non-native reader, I`m not sure that I understand. Could you explain why 100 Kelvin, but 100 degrees Celsius and 100 degrees Fahrenheit? Is there some special meaning in a word "degrees" there?
Now that I think about, what's the etymological reason we use "degrees" to talk about temperature? We don't measure force in "degrees Newton" or electric current in "degrees Ampère". Why do we do it for Celsius and Fahrenheit?