Number Sense Strategies in Solving Decimal Number Problems

Number sense, an intuitive ability about number, including skills to interpret, to manipulate, and to perceive in different roles towards meaning, operation, and ability to solve number. It is considered as a fundamental skill to be mastered by every student to enable them to handle numerical problem in learning mathematics. In this article, we used descriptive research to investigate number sense strategies that used three phases. First, we developed number sense problems on decimal number based on number sense components and gave to two students in grade 7 (12-13 year-old) to solve the problems. Next, we interviewed students to know more about strategy used by student in solving the problems. Finally, we analysed solution from student answers and interview their results. We found that the two students have different strategies in solving the problems. From their solutions, the first student can use number sense strategy in solving decimal number problems, but there are still deficiencies such as, still not understanding the meaning of numbers, having only one way of resolving, and not accompanying the reasons in detail. Furthermore, the second student still performs algorithmic calculations in solving number sense problems on decimal number.