Abstract: This paper deals with the application of a fuzzy set in
measuring teachers- beliefs about mathematics. The vagueness of
beliefs was transformed into standard mathematical values using a
fuzzy preferences model. The study employed a fuzzy approach
questionnaire which consists of six attributes for measuring
mathematics teachers- beliefs about mathematics. The fuzzy conjoint
analysis approach based on fuzzy set theory was used to analyze the
data from twenty three mathematics teachers from four secondary
schools in Terengganu, Malaysia. Teachers- beliefs were recorded in
form of degrees of similarity and its levels of agreement. The
attribute 'Drills and practice is one of the best ways of learning
mathematics' scored the highest degree of similarity at 0. 79860 with
level of 'strongly agree'. The results showed that the teachers- beliefs
about mathematics were varied. This is shown by different levels of
agreement and degrees of similarity of the measured attributes.