The paper brings a discussion about the source of the inaccuracy in observations of objects and demonstrates that the essential reason of the lack of precision is changeability, and the more changeability, i.e. more dynamics, can be experienced the more inaccurate, more fuzzy judges can be. The space of ordered fuzzy numbers (OFN), the new model of fuzzy numbers that make possible to deal with fuzzy inputs quantitatively, exactly in the same way as with real numbers, is shortly presented. The new model possesses a set of properties which are in accordance with the influence of changeability on the increase of the inaccuracy in observations of the environment. The use of OFN is getting rid of the main problem in a classical fuzzy numbers - an unbounded increase in inaccuracies with next calculations. Moreover, new interpretation can be treated as an extend of classic proposals so there is no need to abandon existing ideas to deal with the new model of fuzzy numbers..