Task-Driven: an Effort to Build Secondary Students Mathematical Reasoning Skills

It is already known widely that Indonesian students lack mathematical reasoning skills (MRS) at all level. Many efforts had been taken to overcome the problem. This study aimed to build upper secondary students MRS by means of disseminating an instructional materials, which had been proved valid, practice, and effective from the related previous research. At an amount of 136 tenth grade students from four public schools participated in the study. The students MRS average score for pre-test was 29.3 and 49 for post-test in 100-scale, and the normalized gain was 0.28, which categorized low. Meanwhile, half of the students perceived that the tasks and the learning process lead and drove them to connect and make use of previous knowledge, achieve in-depth understanding, motivate higher, critical, and creative thinking, and enjoy solving problems together in groups.