2.  Any item that is readily accepted by people in return for goods and services.

3.  Exchanging one set of goods for another.  Can result in complicated transactions: how many shells would be equal to 4 shiny rocks?

4.  When producers and consumers agree to provide one type of item in return for another.  If Apple charges $600 for a new iphone, and very few people buy them then the “producers” of the iphone (Apple) know that consumers are not willing to engage in that exchange.

6.  A form of exchange that allows consumers to use items before completing payment for the merchandise.

7.  A way for producers and consumers to determine the worth of items in an exchange.  Value can be expressed as an amount of money, or price.

8.  The degree to which a product is useful to a person.  How many coats do you need in Tucson?

9.  When a society can produce all of their needs and wants with no outside assistance.  True self-sufficiency is rare.

10.  The reliance among economic actors (in other parts of the world or economy) is known as interdependence.