A classical fourfold account begins with material intellect (al-ʿaql al-hayūlānī): the initial receptivity to intelligible knowledge, before its actual development.
The second stage is intellect by disposition (bi-l-malakah): familiarity with basic concepts and necessary judgments sufficient to make further inference possible. A learner who grasps equality, number and simple relations can begin reasoning through unfamiliar problems.
These are conceptual stages of intellectual readiness, not a fixed timetable attached to particular ages. They explain different relations between capacity and actual understanding.