Synthesis is the ability to combine parts of a whole in new and different ways. It requires students to think flexibly, determine alternatives, and find new ways to accomplish a given task. A more advanced level of abstract thinking is needed for synthesis. The 25 lessons in this unit encourage students to go beyond the obvious to more original thoughts. Example: An illustration of a bulb connected to a battery is presented. Electricity is stored in a battery; Look at the accompanying pictures of batteries, wires, and light bulbs. Which bulbs do you think will light up? The sequential activities featured here are sure to develop critical thinking skills.