This study integrated the number sense into the 3(superscript rd) graders' mathematics teaching activities, and then investigated students' number sense performances in their learning processes. One 3(superscript rd)-grade class was purposefully selected from Tao-Yuan County in north Taiwan. The results of the T-test showed that students not only had better performance on number sense, but also achieved the intended learning goals. The results on the parallel test indicated that there is a statistically significant difference between pre-test and posttest at α＜.01. This implies that these students' number sense got much progress after the teaching. Moreover, the process-oriented teaching not only promoted students number sense, but also enhanced students' collaboration, learning motivation and establishing their learning confidence. In sum, the 3(superscript rd) graders' mathematics teaching integrating the number sense situated activities is indeed helpful on developing students' number sense.

三年級 ； 真實數學 ； 過程導向教學 ； 數常識 ； 數常識情境活動

3(superscript rd)-Grade ； Realistic Mathematics ； Process-Oriented Teaching ； Number Sense ； Number Sense Situated Activities