Number Line Estimations, Place Value Understanding and Mathematics Achievement

Current study investigated the relationships among mathematics achievement, place value understanding and number line estimations. We used a curriculum-based math achievement test (MAT, Mathematics Achievement Test), a place value test (PVT), and a mental number line estimation test (MNL) as the data collection tools. A total of 355 fourth graders participated in the study. They were recruited from schools located in middle-low socioeconomic areas of central Anatolia. Correlations were statistically significant among all these tests scores (MAT, PVT, MNL). The highest correlation was obtained between PVT and MAT scores. PVT have also stronger correlations with MNL (0-1000). The average scores of MAT and MNL tests were correlated inversely as expected. The correlations between mathematics achievement scores and MNL (0-1000) was highest. The three MNL tests alltogether have explained 40% of the variance in MAT. Similar to PVT, MNL (0-1000) alone accounted for 36% of the variance in MAT. Meanwhile, MNL (0-1000) (large numbers) contributed MAT more. PVT explained 70% of the variance in MAT. In all tests, PVT contributed more to MAT. Generally, boys did better in all MNL tests but only the result of MNL (0-1000) was significant favoring boys. We can conclude, based on these results that both approximate number acuity and place value understanding contribute to the general math achievement as well as each other. While the place value concept seems to be a representational tool that enhence the acuity of approximate numbers, the relative magnitudes of numbers support place value understanding conceptually.