Cubs sort a list of household appliances in order of energy use then test those appliances to see if they where right. Please note I am not the original author - I just added the file that I created for my cubs to work with. Credit rests with the original author!
Mobile phone (and charger)
Computer and monitor
Lamp with filament bulb
Lamp with energy efficient bulb
Plug in energy monitors (one ber group)
Cubs are given a list of appliances and asked to sort them in order of Electricity consumption.
They are then give an energy monitor and a form and need to test each appliance to see it's actual electricity use.
They compare their results to what the put a the start of the exercise.
The attached file may be of help