While searching Youtube for science activities, I came across an Ellen show clip with science guy, Steve Spangler. The clip showed the two shooting potatoes across the studio. After searching for more of Steve Spangler, the kids and I found some awesome Halloween experiments. You can check out his site here http://www.stevespanglerscience.com/. My kids love his videos from his site. He is very energetic and entertaining. Optimus is very interested in a few of the kits offered on the site.
For Optimus' birthday, his Oma (grandmother) and Grandpa Mike bought him Steve Spangler's book.
It didn't take him long to open it up and start the density project inside.
Tink also wanted to make a similar project. The book is filled with great science facts and experiments. Both of the kids are looking forward to diving in deeper to the book. I highly recommend it! At about $15 you can't go wrong.