Abstract
The aim of this research is to develop a 'program which improves critical thinking' to improve elementary school students' mathematical thinking, and investigate the effect of program by applying and verifying the program. In order to achieve the objective, the author determined the factors of critical thinking capabilities matched to the discipline of mathematics, and accordingly designed relevant programs and test questions for critical thinking skills which contributes to improving the critical thinking of elementary school students, and thus applied the program the developed program of improving the critical thinking to both preliminary and main experiments, which verified the effects of the test method. The following results have been acquired through this research : In the preliminary inspection that this researcher has developed, it was able to predict that 'the program which improves critical thinking' would have a positive influence on the students' critical thinking. In the main experiment which was performed after modifying and supplementing it, the result showed that the program had a positive influence on the students' critical thinking.