本研究將數常識（Number sense）情境教學活動融入國小三年級課室中，主要目的在了解兒童解數常識情境問題之表現，並探討數學課室之教學歷程。因此，本研究採個案研究法，以一班三年級的學生為對象，實施過程導向教學，以探究數常識情境教學的成效。研究結果顯示，學生在教學前後之相同數常識測驗成績經由t檢定分析，結果達顯著水準（ .alpha.< .01），此顯示學生在教學後，不但數常識能力有明顯之增長，原課程之教學目標亦可達到。更由教學中的師生互動、學生的解題記錄和觀察資料中發現，數常識情境教學活動不但建立了學生的數概念，也提升了學生的數常識能力，培養學生閱讀題目的習慣，增進學生對題意的理解。此外，過程導向教學有助於提升學生的數常識，透過教師的鼓勵與同儕間的互助合作，提升了學生的學習意願，建立學習的信心。

This study integrated the number sense into the 3rd graders' mathematics teaching activities, and then investigated students' number sense performances in their learning processes. One 3rd-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 .alpha.< .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' col-laboration, learning motivation and establishing their learning confidence. In sum, the 3rd graders' mathe-matics teaching integrating the number sense situated activities is indeed helpful on developing students' number sense.