THINKING STRUCTURES AND MATHEMATICAL ACHIEVEMENTS IN CHILDREN WITH MILD INTELLECTUAL DISABILITIES

The development of thinking structures in children has a significant influence on their mastering of mathematical concepts. The appearance of concrete logical thinking and its indicators (conservation concepts) influence positive school achievement regarding mathematical contents. By shaping the formal operations which represent the final and supreme phase of cognitive development, the most complex forms of conservations become available. Combinatorics is a feature which belongs to the last phase of cognitive development; it represents the generalization of the operations acquired in the concrete operational stage. The purpose of this paper is to analyze the development of the operational thinking structures in relation to concrete logical operations (using the conservation of number, length, mass and volume) and formal operations (using combinatorics) as well as thei