ABSTRACT
We might begin, as we did in our study of the understanding of distance and length, by asking whether little children think of an area as a stable attribute which may be conserved even while the shape of an object is altered. This question must be answered before we study the metric relations involved. To find how this kind of conservation is constructed we adopt our usual method of showing children an area which is made up of sub-areas organized in one way, and then altering the apparent structure of the whole while they look on. Does the whole remain invariant in spite of the rearrangement of its parts? Later on we shall ask how the parts themselves are compared with one another at different ages, and how their comparisons eventually give rise to metric operations.
