From their site:
For the month of May 2011, Scientific American will feature one science- related activity each weekday, which parents and their six- to 12-year-olds can do together. We consulted with members of the National Science Teachers Association so that the activities would echo themes taught in early grades. Parents will also find additional background to help them explain the concepts. But the overarching goal was simple: each activity had to be easy and fun, done with household ingredients and completed in less than an hour.