Chapter 2: Solving One-step Equations and Inequalities

#1019 Making Sparks: Where Energy Comes From—When you turn on your lights, you are plugging into a power grid which is fed by fossil fuel, nuclear and hydroelectric power plants.

Ask students to identify variables as they watch Futures Channel Movies #1019 Making Sparks: Where Energy Comes From and #1021 Making Sparks: How It Works (if you have time, show all three Making Sparks Movies in sequence, but it isn’t necessary).  In discussion, elicit or bring up the variables of “amount of energy”, “power”, and “time”, and make sure students understand the energy formula described in Movie #1021 (energy = power x time).  Explain to students that people who work with energy use algebra to describe relationships between variables and to solve problems related to their work, and that in this chapter the students are going to learn more about how algebra can help them solve such problems.