With the reforms regarding the curriculum contents more attention is paid to the teacher-pupil activity ratio in teaching-learning process that requires the search of new scheme of its participants’ interaction. The article discusses some peculiarities of new methodology in work system of teaching based on doing word arithmetic problems at the lessons of Mathematics at Primary School. Traditional method allows pupils just to study the example and keep in mind the ways of solving the arithmetical problems. It fails to develop good skills in doing arithmetic problems, besides it does not help to develop pupils’ deep thinking. In our opinion, acquiring good common research skills while doing tasks referring to the problem is the way out. In order to develop young learners’ good skills of conscious doing word arithmetic problems it is necessary to use many different possibilities of their solving by working with the learners after they have done them