At what stage does a child begin to understand the concept of conservation according to Piaget?

The correct choice is the concrete operational stage, which spans from approximately ages 7 to 11. During this stage, children begin to grasp the concept of conservation, which refers to the understanding that certain properties of objects, such as volume, mass, and number, remain the same even when their shape or arrangement changes. For instance, if water is poured from a short, wide glass into a tall, narrow glass, a child in the concrete operational stage would recognize that the amount of water remains constant despite the change in appearance.

This developmental milestone signifies a shift from earlier cognitive patterns characterized by egocentrism and intuitive thinking found in the pre-operational stage, where children may struggle to understand the logic behind conservation. The concrete operational stage equips children with more logical reasoning abilities that allow them to comprehend complex relationships and manipulate mental representations of objects. Understanding conservation is crucial as it lays the foundation for more advanced mathematical concepts and scientific reasoning that children will encounter in later stages.