**Author details**

Ionuţ-Constantin Manole1\* and Eugen Petac2

\*Address all correspondence to: manole.ionut@gmail.com

1 "Ion Creangă" State Pedagogical University, Department of Education Sciences, Chişinău, Moldova

2 "Ovidius" University of Constanța, Department of Mathematics and Computer Science, Constanța, Romania
