Communicating their thinking in mathematics is challenging for young children. This research studied the change in six-year old students' oral and written solution explanations before and after six problem-based mathematics lessons that focused on developing conceptual understanding of adding or subtracting a 2-digit number and a multiple of ten.…

Visual representations play an important role in science teaching. The way in which visual representations may help children to acquire scientific concepts is a crucial test in the debate between constructivist and socio-cultural oriented researchers. In this paper, the question is addressed as a problem of how to contextualize conceptions and…