Each group needs:

• 1 electrical appliance, such as a blender, drill, electric tooth brush, cell phone, phone charger, computer or laptop, copier, overhead projector, TV, boom box, holiday lights (old, big incandescent ones and new LED type); groups rotate through these items
• watt meter (for example, do an Internet search for "Kill-A-Watt EZ Plug Power Meter" or "Watts Up Portable Plug In Power Meter," $20-$100 each)
• Student Worksheet, one per student

To share with the entire class:

• Enough extension cords/power strips so that all appliances can be plugged in. Especially note how much space the watt meter takes; on most standard wall outlets it is not possible to plug in two simultaneously.