The calculation method ABN (Open Number Based Algorithms) promotes numerical sense, calculation and problem solving through direct experience and the handling of objects.

The actions they perform with them, everyday objects such as toothpicks, buttons, pegs or rubber floors numbered from 0 to 9, since this direct experience can not be replaced by verbal learning that forces an abuse of memory, and that fails to make sense of what has been learned. The child must build their own learning, be an active agent of their learning, and it is we, the school, who are in charge of providing these experiences so that the children can build mathematical knowledge about what they already know and about those situations to which They have already found an explanation, about what has already made sense for them.

Why all students are required to learn the same, in the same way, at the same time and at the same pace, if each student has their capacity, their style and their pace of learning, instead of appreciating as meritorious?

It is difficult for the student to be able to learn as complicated as the one offered, it is judged that this is normal, and that those who are not able to do so are the ones who fail, the incapable, those who are not the height‘. (Martínez Montero, 2010).

What characterizes this teaching methodology is its open and flexible nature, which makes it possible to adapt its algorithms to the individual rhythm of each child, allowing the unfolding and granting facilities in the calculations, impossible to find in traditional formats, algorithms with the that it is possible to find the correct solution in different ways. and the fact that the base on which the student works are the numbers, where the units, the tens, the hundreds … are composed and decompose freely without applying a certain rule or criterion for its final resolution.

The ABN Method begins to be used from the Infant stage (3 years) and closes in 6th grade with contents of initiation to the Secondary stage. As an open and natural methodology, students learn at their own pace, with close situations and manipulable materials.