From birth to 5 years old, the child discovers the world around him by operating the first classifications and the first thought pattners through the use of the senses. Important Stimulus receives from the environment in which he lives (family ,school ) are important because prepares concepts and schemes based on his own experiences.
Between 6-7 years in mathematics learns the four operations and the representation of relationships : the thought becomes reversible. Also the “construction ” of sets supports the formation of abstract thinking.
From 12 to 13 years, the thought is able to build abstractions based on the “structures” of mathematics.