Achild understands that if an elephant is bigger than a bear and a bear is bigger than a cat, then an elephant is bigger than a cat. this demonstrates the child's understanding

This demonstrates the child's understanding of TRANSITIVITY.

Explanation:TRANSITIVITY can be said to be the relationship between different objects such that if an object x is related to y and y is related to z, then x is necessarily related to z. Like in the example above, the child is able to relate the property (size) of the elephant, bear and the cat. This demonstrates TRANSITIVITY

the telephone is the answer

the answer to your question is,

old stone age.

-mabel < 3