G. Cantor : Das Wesen der Mathematik liegt in ihrer Freiheit. (Freedom is the essence of mathematics.) One of the main objectives of school mathematics education is to develop a student`s intuition and logical thinking [11]. But two-valued logical thinking, in fact, is not sufficient to express the concepts of a student`s mind since intuition is fuzzy. Hence fuzzy-valued logical thinking may be a more natural way to develop a student`s mathematical thinking.