Both Mohan and Rohan respond correctly to the famous water jar problem (according to which child perceives that the tall glass has more water than the thick glass even though they both actually carry the same amount of water). This illustrates that they have developed ______________(according to Piaget).

Reversibility: In Piaget's theory of cognitive development, the third stage is called the Concrete Operational stage. During this stage, which occurs from age 7-12, the child shows increased use of logical thinking. One of the important processes that develops is that of Reversibility, which refers to the ability to recognize that numbers or objects can be changed and returned to their original condition. For example, during this stage, a child understands that a favourite ball that deflates is not gone but can be filled with air again and put back into play.