The geoboard

The geoplano was created by the Egyptian mathematician Caleb Gattegno about 1960, who was looking for a method to teach geometry in a more didactic way. Although today most of them are made of plastic, the original consisted of a square wooden board with nails forming a weave, in such a way that these protruded and could be hooked elastic bands that will serve to represent the different geometric figures.

This consists of a square board of variable size (usually wooden) that has been squared and is determined by a number of these grids. It has a nail in each vertex which protrude about 2cm generally.
On the base, rubber elastic bands are placed that are fastened on the nails forming the desired geometric gums. With the geoplane, geometric shapes can be formed using said elastic rubbers; establish similarities and differences between parallelism and perpendicularity; use a graphic-algebraic language.

Due to its manipulative nature, it allows students a greater understanding of abstract terms, which often they do not understand, or generate misconceptions. With it we can not only measure polygon sizes (counting grids), we can solve mathematical problems, learn about areas, perimeters, etc. it is definitely an essential resource to learn mathematics.

The geoplane is a very interesting didactic resource for working the measurement because you must know how much the board measures to know which grid you have to make. It helps teachers to introduce the measurement in a manipulative way. It can be used with students of all ages, individually, in groups or the teacher can use it to show it to the whole class or to explain the class. On the other hand, this can be introduced at the beginning of primary school for the child to manipulate, play and learn by himself. At this stage it can be fun to make your own geoplane yourself.

The teaching process occurs in a creative way through group activities, in which the teacher asks questions directed by the teacher. In this way, it helps students to construct their answers and at the same time to ask their own questions, creating their own conjectures about a mathematical concept.


TYPES OF GEOPLANO

1. The orthometric geoplano (or square geoplano):
It is squared, the most frequent are those which have 25 points.

2. The isometric geoplano (or triangular geoplano):
It is triangular. The points are located at the vertices of equilateral triangles.

3. The circular geoplano:
It is a collection of points on a circumference that are spaced at the same distance. Normally it has 24 points. It allows to build regular polygons of 3,4,5,6,8,12 and 24 sides.
It also is useful to study the properties of the elements of the circumference and of the figures subscribed in it.