The purpose of this study is to identify the influences of the reciprocal writing-reflection activities on the mathematical learning of the 2nd grade students by developing a class model using reciprocal writing-reflection activities method as one of the interactive application of manipulative activities, reflective thought and communication activities which are the learning principles of constructivism. We have experimented and investigated to after dividing experimental objects into two group, experimental groups and comparative group, The conclusions of this study are followings. First, reciprocal writing-reflection activities showed significant effects on mathematical achievements of the group with lower achievements in learning. Second, reciprocal writing-reflection activities positively influenced mathematical tendency of the students. Third, the students had positive attitudes in interest, desire and usefulness regarding reciprocal writing-reflection activities. And reciprocal writing- reflection activities are helpful for their reflective thinking and communication activities.