Relations and functions (video) | Khan Academy
https://www.khanacademy.org/math/cc-eighth-grade-math/cc-8th-linear-equations-functions/cc-8th-function-intro/v/relations-and-functions
WebScenario 1: Suppose that pressing Button 1 always gives you a bottle of water. Pressing 2, always a candy bar. Pressing 3, always Coca-Cola. Pressing 4, always an apple. Pressing 5, always a Pepsi-Cola. There is a RELATION here. The buttons 1, 2, 3, 4, 5 are related to the water, candy, Coca-Cola, apple, or Pepsi.
DA: 22 PA: 13 MOZ Rank: 85