In his multiple Intelligences Theory, Howard Gardner states that every human being has at least eight intelligences: Verbal/Linguistic, Musical/Rhythmic, Visual/Spatial, Bodily/Kinesthetic, Interpersonal, Intrapersonal, Naturalist.
Gardner also argues that in traditional methods of teaching, the teacher activates only verbal and mathematical intelligences, which results in the educational failure of the students who are better at other Intelligences. In this study, various tasks activating the students' different Intelligences were designed, through which their performance in mathematics was investigated.
The participants were selected from junior high-school students in Shahryar in the academic year 2001-2002. A quasi-experimental design was used to select two schools randomly, which were then divided into the control and the experimental group. Before the treatment, the students were given a pre-test to investigate their background knowledge and after the treatment, they were given a post-test. The questions of the post-test were based on the mathematics cognitive domains of TIMSS 2003, covering the four levels of knowing, using concepts, solving routine problems and reasoning. In order to examine the content validity of the pre-test and the post-test, the experts' opinions were consulted. The coefficient alpha for the reliability of the tests were.78%and .82%. The results revealed that the performance of the students who were taught based on Gardner's theory was better than that of those taught through the traditional method at all levels.