8ccb22b7_Math_Maturity___IAE_Pedia__Math_Cognitive_Developments
[Stage & Name] Level 4. Piagetian and Math formal operations. After age 11. [Math Cognitive Developments] 
Starting at age 11 or 12, or so, thought begins to be systematic and abstract. In this stage, intelligence is demonstrated through the logical use of symbols related to abstract concepts, problem solving, and gaining and using higher-order knowledge and skills. Math maturity supports the understanding of and proficiency in math at the level of a high school math curriculum. Beginnings of understanding of math-type arguments and proof. Piagetian and Math formal operations includes being able to recognize math aspects of problem situations in both math and non-math disciplines, convert these aspects into math problems (math modeling), and solve the resulting math problems if they are within the range of the math that one has studied. Such transfer of learning is a core aspect of Level 4. Level 4 cognitive development can continue well into college, and most students never fully achieve Level 4 math cognitive development. This is because of some combination of innate math ability and not taking cognitively demanding higher-level math courses, or not pursuing similar equivalent studies in other courses and/or on their own.
Math Maturity - IAE-Pedia
Math Cognitive Developments