Thema: 33 centimetres plus 1/3 of a centimetre as well, together, summed, in total.
lolol. Pedanticsemantics. Okay, backgammon be damned, I'll join in too.
Walter is quite correct with his original "33 and 1/3 centimeters" (apart from it being centimetREs in *proper* English, hee hee). Due to the use of the plural there's no option to construe the 33 as merely a number and the 1/3 as the measure.
"1/3 centimetres" is incorrect English. It would be "1/3 centimetre" which is shorthand for "1/3 of a centimetre". Writing "1/3 of a centimetres"? Well, you can see how wrong that is. (Though, interestingly, the plural is correct for decimal fractions, eg 0.5 oranges)
Therefore, when Walter says "33 and 1/3 centimeters", the plurality, and hence the centimetreness, must cover the 33 as well.
Chessmaster1000; I didn't understand why you said "better not to use plural". If I say "It measures 2 centimetre." then it feels as if I'm talking like a foreigner.