Abstract: This paper reports preliminary results of a longitudinal study of children’s understanding of decimal notation. A large sample of students completed a short test that enabled their understanding to be classified into four categories and changes over periods of up to two years to be tracked. When they attained expertise, students almost always retained it, even if it is simply following memorised rules. A small core of students retains “longer-is-larger” misconceptions. In contrast, students seem to move in and out of “shorter-is-larger” misconceptions. Improvements and hypotheses to be investigated in the future are noted.
Stacey, K., & Steinle, V. (1999a). A longitudinal study of children's thinking about decimals: A preliminary analysis. In O. Zaslavsky (ed.), Proceedings of the 23rd Conference of the International Group for the Psychology of Mathematics Education, Haifa, Israel.