Answer:
Formal operational
Explanation:
According to Jean Piaget theory of cognitive development, infants and adolescents go through different stages of cognitive development. During these stages they develop new cognitive skills and their thinking becomes more formal.
The last of these stages is known as the Formal Operational stage and it takes place from age 12. During these stage, the kids start to think in abstract and logic forms to address problems and come out with new solutions. During this stage, kids develop the ability to think about abstract concepts without their sense's aid. They also start thinking about the possible outcomes of their actions before they take place.
Thanks to this logical and abstract thinking, they can also start understanding and dealing with subjects such as algebra which requires them to be able to have an abstract thinking.
Therefore, it is during the formal operational stage of cognitive development is the mastery of logical and abstract thinking of paramount concern
