This short video by the Khan Academy presents a classic introduction to economic teaching. Starting with the quote by Adam Smith in "The Wealth of Nations" on the invisible hand, it shows how economics deals with the question of the allocation of scarce resources and shortly presents different questions addressed by microeconomics and macroeconomics. It further makes reference to questions of simplification in mathematical models.
Go to: Introduction to economics | Supply, demand, and market equilibrium | Microeconomics