ABSTRACT
Although area and volume are closely related geometrically, the question of volume raises many problems of its own. It is intimately bound up, psychologically, with physical objects, and indeed we cannot ask children about the conservation of volume without introducing physical objects like bricks or cubes filled with sand, etc. A question which thus arises is how far the understanding of conservation of volume can develop through the qualitative appreciation of the conservation of a given amount of substance. Or does this understanding have to wait for the construction of a spatial continuum and the notion of space as such, whether occupied or unoccupied?
