Chapter 1: Operations with Numbers

Introduce or review the concept of variable as “a quantity that changes, usually represented by a letter”.  Ask students to watch for variables as they watch Futures Channel Movie #5001, Water Supply.  After the movie, discuss the variables observed, such as amount of water needed, the population of the city, how far the water travels, and how fast the water moves.

Ask whether it would be important to be able to predict the values of some of these variables, such as the population of a city 10 years from now, and why. Discuss some answers.