Appropriate grades or age groups:
4th-6th

Estimated time to complete this project:
1 day

Materials:
4 soap cleaners -- 2 expensive brands and 2 cheap brands

Instructions:
1. Take one of the soap cleaners and try it out on the kitchen floor (your kitchen floor has to be dirty)
2. Do the same with the others and observe which one cleans the best
3. That's it. Bravo. Now make sure that the one that works is the one that you and your friends and family buy!

Other comments or suggestions:
You can try it with as many different kinds of brand make it more complicated - WOW!