Final answer:
Logical reasoning about concrete objects begins in Piaget's concrete operational stage, from ages 7 to 11, where children grasp mathematical operations and conservation.
Step-by-step explanation:
Logical reasoning about concrete objects typically kicks in during Piaget's concrete operational stage, which occupies the age range of about 7 to 11 years old. During this stage, children begin to think logically about real (concrete) events. They can perform mathematical operations and grasp the concept of conservation, meaning they understand that the amount of something remains the same even if its appearance changes. For instance, they know that pouring water from one container to another doesn't change the amount of water.