What is a key developmental milestone of the Concrete Operational Stage?

• A. Symbolic thought
• B. Ability to conserve numbers
• C. Ability to form schemas
• D. Abstract thinking

Answer: (B)

The ability to conserve numbers is a key developmental milestone in the Concrete Operational Stage, which typically occurs between the ages of 7 and 11, according to Piaget's stages of cognitive development. During this stage, children begin to think logically about concrete events and understand the concept of conservation, which means they understand that quantity doesn't change even when its shape does. For example, if you take two identical balls of clay and flatten one into a disc, a child in this stage recognizes that both shapes still represent the same amount of clay, demonstrating a more advanced understanding of mathematics and problem-solving.

In contrast, symbolic thought and the ability to form schemas are more characteristic of the earlier Preoperational Stage, while abstract thinking is a feature of the subsequent Formal Operational Stage. Therefore, recognizing the ability to conserve numbers distinctly marks the transition into more sophisticated reasoning and logical thinking, which are hallmarks of the Concrete Operational Stage.