12th International Congress on Mathematical Education Program Name XX-YY-zz (pp. abcde-fghij) 8 July – 15 July, 2012, COEX, Seoul, Korea (This part is for LOC use only. Please do not change this part.) INTRODUCTION OF FRACTION BY MEASUREMENT AND THEIR IMPLICATION Hyo jin Lee, Kwang ho Lee Guenhwa elementary school, Korea National University of Education cnuesu@hanmail.net, paransol@knue.ac.kr INTRODUCTION & STUDY METHOD Students who have learned without understanding the generative processes and necessity of the fraction, do not associate their existing mathematical knowledge with fraction. Many researchers asserted the necessity of teaching introduction of fraction through distribution and measurement. There are few researches which develop and apply to the program introducing fraction by distribution and measurement. The purpose of this study is to suggest an implication about the learning effect of program introducing fraction by measurement to 2nd graders. The program introducing fraction by measurement developed in this study is composed to distribution, measurement and comparison situations. We selected five 2nd graders and gathered video recordings (40 minutes×6 times), sound recordings and worksheets of learning. STUDY RESULT Students elaborated fractional expression following the steps such as using of picture or household word, replacing denominator with number and replacing numerator with number. They used existing mathematical knowledge beyond the expectations in the process of expressing unit fraction or proper fraction. Existing mathematical knowledge using students is symbols such as +, -, × and =, the principle of addition of natural number, the principle of addition same number repeatedly and characteristics of the figure (○, △ and □). Students took a pride in their new expressive method to be free from repetition and misunderstanding. But students had difficulty to distinguish between relative and absolute amount and recognize relative amount. And they did not understand that size can be same, irrespective of shape. CONCLUSION The merit of introducing fraction by measurement is that students can experience the generative processes of the fraction dynamically through reasoning, justification, proof and confutation, agreement and reappearance in active communication. Then students can become mathematician which solve problem in the real world. abcde