Conservation is the realization that quantity or amount does not changewhen nothing has been added or taken away from an object or a collection ofobjects, despite changes in form or spatial arrangement (Pulaski, 1980).

Jean Piaget used the idea of conservation in a set of experimentsgeared at studying children's ability to think and reason. Piaget realized thatmaturing children progressively master different types of conservation as theyreason about their world. The cow figure below represents conservation of area.When a child realizes that cows eat the same amount of grass regardless of thespatial location of the grass , they can conserve area.

According to piaget, a student's ability to solve conservation problemsdepends on an understanding of three basic aspects of reasoning: identity,compensation, and reversability.

With mastery of identity: The student realizes that materialremains the same if nothing is added to or subtracted from the material.

With mastery of compensation: The student realizes that changesin one dimension can be offset by changes in another.

With mastery of reversibility: The student realizes that achange may be canceled out by mentally reversing the steps and returning to theorigin.