This 10 page packet includes a printable poster which can be blown up to a bigger size, a graphic organizer, a practice sheet, and a matching game. I use these activities when teaching my own unit on decimal fractions to my third graders.
I also use a PowerPoint presentation which you can find at my TpT store. Please see my blog entry about Decimals: Understanding that Little Dot at http://tricksoftheteachingtrade.blogspot.com/2012/02/decimals-understanding-that-little-dot.html
to see other teaching ideas and my favorite videos for teaching decimal fractions.