Abstract
This paper reports a longitudinal study of children's understanding of decimal notation. The
understandings of 3211 students were classified into four categories and changes over long
periods were tracked. The progress of sixty-four students over about three years is reported.
When expertise is attained it is generally retained. Over about a year, many students remain
in the same misconception category, but in the longer term they move between misconceptions.
Improvements and hypotheses to be investigated in the future are noted.
Kaye Stacey & Vicki Steinle
UNDERSTANDING DECIMALS: THE PATH TO EXPERTISE