At approximately what age do children begin exhibiting the feature of conservation according to Piaget?

The concept of conservation, as proposed by Piaget, refers to the understanding that certain properties of objects, such as volume, mass, and number, remain the same even when their form or arrangement changes. According to Piaget's stages of cognitive development, children typically begin to grasp the concept of conservation during the concrete operational stage, which occurs roughly between the ages of 7 and 11.

At around 6 years of age, children are still in the preoperational stage, where they may struggle with tasks that require understanding conservation. It's only when they reach around 7 years old that they start demonstrating an understanding of conservation in practical tasks, such as recognizing that the amount of liquid remains the same when poured from one container to another, even if the shape of the container changes. This cognitive development milestone is significant as it reflects a deeper understanding of the physical properties of objects and moves beyond the intuitive and egocentric reasoning that characterizes earlier stages of development.