Understand how markets and the whole economy actually work — the principles behind AP Microeconomics, AP Macroeconomics, and an intro-college course, taught so they click. On the micro side: scarcity and opportunity cost, supply and demand and how a market finds its equilibrium, elasticity and the total-revenue test, the costs of production, the four market structures (perfect competition, monopoly, oligopoly, monopolistic competition), externalities and public goods, and what price ceilings and floors really do. On the macro side: GDP and how it is measured, inflation and the CPI (real versus nominal), unemployment, the aggregate-demand/aggregate-supply model, fiscal and monetary policy, money and banking and the money multiplier, exchange rates and comparative advantage, and long-run growth. A neutral comparative-systems strand covers what capitalism, socialism, and a mixed economy actually denote as systems — definitions and trade-offs, never advocacy. Many questions have a computed, always-correct answer (equilibrium, elasticity, multipliers, gains from trade), and every explanation names the classic trap — confusing a shift in demand with a movement along it, reading nominal growth as real — and leaves you a rule. Educational only — how the economy works, never personal investment advice. Independent, not affiliated with the College Board.