Abstraction

Abstraction is the process or result of generalization by reducing the information content of a concept or an observable phenomenon, typically in order to retain only information which is relevant for a particular purpose.
In philosophical terminology, abstraction is the thought process wherein ideas are distanced from objects.
Abstraction uses a strategy of simplification, wherein formerly concrete details are left ambiguous, vague, or undefined; thus effective communication about things in the abstract requires an intuitive or common experience between the communicator and the communication recipient.
Abstraction in mathematics is the process of extracting the underlying essence of a mathematical concept, removing any dependence on real world objects with which it might originally have been connected, and generalising it so that it has wider applications.
Many areas of mathematics began with the study of real world problems, before the underlying rules and concepts were identified and defined as abstract structures. For example, geometry has its origins in the calculation of distances and areas in the real world; statistics has its origins in the calculation of probabilities in gambling; and algebra started with methods of solving problems in arithmetic(http://www.wikipedia.org/)

The process of abstraction in learning mathematics can utilize the psychological development of children. The process of learning math in kindergarten, elementary school to junior high schools should start with the materials from which concrete. Therefore, the learning process must use the tools of mathematics. Tools of mathematics can be made by the teachers themselves, without cost. It seems that many teachers think that the use of tools to make the learning process is too long and not practical. Teachers may also have less ability to simply use the tools in the learning process. The establishment of the concept will be built from solid materials into the abstract in the minds of students. By using the tools, the construction of understanding of mathematics concepts will be good