The root of the word abstract means something pulled away or drawn away. In educational terms it means perceiving the essence of an idea and no longer needing a concrete representation of the idea. An example would be grasping the idea that 2 plus 2 equals 4, no longer needing to see material objects of four items. (Boehnlein)

“We ask what is the first act of intelligence, it is reasoning; and we have observed its apparition in a child of three weeks of age. It is the act of reasoning by which they orient themselves, upon which all moves. As the intelligence develops, they come to move between cause and effect, to reason out things and their results, the beginning and the end, and little children starting from a single number go towards infinity… Now the other power of which I am speaking is that of abstraction. The mind is formed of abstractions which it has drawn from material things.” (Montessori, Maria, Communications, 2009,4, p. 40 “Cosmic Education Sixth Lecture by Dr Maria Montessori on 14th January 1936 21^st International Training Course Extension.”) “Language is not just a means that mankind has of communicating its needs, man to man, but it is a means of flight into abstraction. Number, too, is in the realm of abstraction.” (Montessori, Maria, Communications, 2009, 4, p.40. “Cosmic Education Sixth Lecture by Dr. Maria Montessori on 14^th of January 1936 International Training Course Extension.”)