When if it catches a ribbon of 1000mm parting itself in three equal pieces, each piece mathematically has a length represented for 333,333333 mm, where it not only appears an infinite amount of digits 3 and fifteen digits 3. When adding, we get 999,999999 mm, where it not only appears an infinite amount of digits 9 and fifteen digits 9, as it describes the question. In this way, what it is in game is: that number is this that is represented by an infinite amount of decimals? I go definiz it. They are S1=999,9; S2=999,99; S3=999,999; ; Sn=999,999 9, that is, n you novate the comma after. For definition, 999,999 (infinite you novate) are the lesser number that is greater that Sn for all N. Is proved that 1000 satisfy the definition above.

Soon, the addition of the three parts is 1000.' ' (p.43) This example illustrates in them colon of sight, preset, one wanting to argue and to overlap it the other, not mattering in reflecting on its arguments, nor in clarear its vision of the other. In the truth, a dialogue was not established, only one and another one speaks, under its point of view, in its language and closed in its interests. Unhappyly, it is also this that many times occurs in classroom. The pupil speaks of a thing, makes a questioning and the professor in turn, when answering it, speaks of other things, they do not understand and ' ' if they go felizes' ' life measures, for not dedicating themselves to the understanding of the perspective of the other, or at least conceiving that the numbers and the Mathematics can have different dimensions. Mathematical abstraction ' ' Abstract and concreto' ' , in the sense of the common man it so clearly does not exist nothing more easy of if separating, nothing so dicotmico. The abstract deals with things of the imagination, the thought, the ideas, the not-concrete one, the intangible one, the inefvel.