Sand tray and ice cubes i would link in the following:
From birth, children are actively engaged in constructing their own understandings from their experiences, Young children actively learn from observing and mixing with other children and adults, including parents and practitioners. Children need to form their own ideas and keep trying them out through social interaction, physical manipulation, and their own thoughts observing what happens, reflecting on their findings, asking questions, and forming answers.(ref Piaget 1952; Vygotsky 1978; Case & Okamoto 1996)
(ref (
http://www.naeyc.org/about/positions/dap3.asp)
Piaget
His work encourages practitioners to provide a stimulating environment that encourages children to learn and develop their understanding of the world around them, children need to develop their own understanding of concepts and build mental structures for themselves, Piaget concluded children’s learning is developmentally based and they go through stages changing their views of previously held concepts.
Piaget acknowledged that children develop at different rates and go through different stages and that the curriculum needs to reflect these differences. (Ref Daly, Byers, Taylor 2006 p46)
hope thats a bit of help there may be others you could use.