Figuring out math concepts relates to the cognitive dimension of human development.
Cognitive dimension involves thought process construction, analysis, how children figures things out. This includes problem-solving, disposition, decision-making. Some of the significant Cognitive Development Milestones are (1) recognizing of sizes and shapes (children 3-4 yrs. old) and (2) counting numbers 1 to 5 (children 4-5 yrs. old).