Verified answer

It doesn't stand for anything, just multiply the 9/5 into the equation.

OK, in the Fahrenheit scale, the number of degrees from freezing to boiling is 180 degrees, and in the Centigrade/Celsius scale, 100 degrees, that means there are 1.8 degrees F in one degree C...

which means the formula given in the question is wrong.

It should be F = 5/9C + 32.

example: if you have 0 degrees C, that means freezing is 32F, which is correct.

Edit: Just so I don't leave you hanging, if you rearrange the equation, you get

C = 9/5 (F-32)

nine fifths

its just an arbitrary relationship