Maria Montessori stresses prepared environment as the most important principle of Montessori pedagogy. Didactic materials, which are the part of prepared environment, stimulate a child to be active, independent and induce a state of deep concentration. Working with the concrete materials, through sensory experience, a child understands abstract concepts. Maria Montessori noticed that math is an abstract concept and it is necessary to make it more concrete so that a child could understand better. She paid the most attention to mathematics and developing mathematical materials, so today the math area is the most extensive area in Montessori pedagogy. In the first four classes of elementary school, according to Piaget, the child is at the stage of concrete operations (Buggle, 2002). This level of education is the base for the further mathematical education. To be able to understand mathematical concepts, child must manipulate with concrete objects or didactic materials. A variety of didactic materials, carefully crafted to the smallest detail, which are part of the Montessori classroom, could easily become part of every classroom in state public school. How often, how and why the Montessori materials can be used in the ordinary teaching of mathematics is described in study carried out for the purposes of this paper. The study tried to explore willingness, affinity and attitude of pupils about math lesson organised with the help of mathematical Montessori materials and the effectiveness of teaching mathematics according to the Montessori principals. The study presented in this thesis was undertaken on a sample of 78 pupils of first and fourth grade of primary schools. The results showed that attitudes of pupils about mathematics are positive, that the pupils love Maths (girls love math more than boys; first graders love math more than fourth graders), pupils evaluate their mathematical competencies high and they perceive maths as a neither too difficult nor too easy. Pupils reacted excellently to the use of the Montessori materials in Maths lesson. Materials made the comprehension of the new content easier and also helped to make revision more active and fun. Pupils state that they would like to use different 3 materials and games in math lessons more often and they graded Montessori lesson of mathematics with high grades.