Jean Piaget believed that knowledge acquisition is a self constructive process. He believed that knowledge lies within the individual and it is not out there. He emphasized that children construct their knowledge from their surroundings. He suggested three areas or types of knowledge, (social, physical, and logico-mathematical) to development, and to theories of learning.It is argued that instruction can be more specific in some ways, as in the teaching of social knowledge, and in the structuring of cognitive processes that will eventually result in logical thinking.Numbers come under logico-mathematical knowledge as numbers are the relationships a child creates mentally and in the logico-mathematical realm, the child's knowledge is based on his own reasoning rather than on external sources.Piaget believed that social and physical knowledge is built from sources that are external to the child, but logico-mathematical knowledge is structured from the internal consistency of the system that the child has already built.For example, If I take out 10 cups and 10 saucers, there will be as many cups as saucers even if their spatial arrangement is changed.HintPhysical Knowledge: This type of knowledge is also called empirical knowledge, it mainly deals with knowledge acquired through interaction with the world and through the perception of the objects.Social Knowledge: This is related to one's culture and can be acquired through interaction with their own community. The ultimate source of social knowledge is people and the childcan acquire it only from people.Hence, from the above discussion, it is clear that numbers come under logico-mathematical knowledge as numbers are the relationships a child creates mentally is the correct answer in the context of the question.