In this paper, we explore the possible value of an open-ended assessment task, Impress Me, and followup
interview as ways to gain insights into children’s learning of mathematics,. Ten children in their first
or second year of school recorded their understanding using drawing and/or writing after the period in
which they were taught lessons on the measurement of mass. Later they met individually with an
interviewer/researcher to discuss their drawing/writing and their learning. The Impress Me recording was
found to be a useful prompt for the children to stimulate discussion about their learning.