Object orientation appears congenial to human problem solving facilities. Object-oriented ideas permeate mathematics. It saved software industry by enabling common programmers to produce sophisticated and reasonably reliable software. Even more importantly, it made the software maintenance task feasible. In the automotive industry, it resulted in cost reduction by standardizing parts between various cars.
Technology moves into the classroom.
This may be the right time to move there the underlying methodology as well. Present concrete with abstract in mind. Concrete problems must be presented so as to underscore their similarities and differences. Do not mix different concepts in a single concrete device. For example, counting has nothing to do with the numerals or the decimal system.