I have to correct your correctness:
A third of a meter is not 33.33 centimeters.
It's not even 33 and 1/3 centimeters.
It is (33 + 1/3) centimeter or (33 + 1/3) centimeters (better not to use plural but it's acceptable too (if you have used the cm prefix instaed of the whole word, then the cms would not be acceptable) ..........