Answer:
Concrete operations
Explanation:
Concrete Operational Stage: This is the third stage in the cognitive-developmental theory given by Jean Piaget. This stage starts from the age of seven and lasts through the age of eleven years i.e, the time during middle childhood.
In the concrete operational stage the child becomes mature enough to implement logical operations or thought, for example, rules and regulations yet are only able to implement this logic to physical objects that is why it is known as concrete operational.
Conservation is one of the major characteristics of this stage.
Example: A child can differentiate between the amount of a liquid that will remain the same if nothing is taken or added in that liquid.