Nejla Gürefe^1,, Ceren Öncül², Hasan Es³

In this study, it was examined achievement in middle school students' number sense and its sub-dimensions according to various variables. Number sense means that people can make logical estimates about various uses area, be able to recognize arithmetic errors and number patterns, to choose the most effective way of calculation. Number Sense Scale consists of three dimensions: Flexibility in Calculation, Conceptual Thinking in Fractions, and Using Benchmark (reference points). Unrelated samples t-test, one-way Anova, two-way Anova, and Kruskal-Wallis analyzes were used to determine whether students' achievements in total and sub-dimensions of number sense scale differed significantly in terms of gender and grade levels. From findings obtained from the research, there was no meaningful difference in the students' achievement in numerical sense total and sub-dimensions in terms of gender and in using benchmark (reference points) in terms of grade level. However, there was a meaningful difference in the number sense total, flexibility in calculation and conceptual thinking in fractions scores. It has been determined that this is in favor of 8th grade students.

number sense, dimensions of number sense, mathematics