If you teach fractions (especially with a Common Core approach) and haven't been following along with Meg over at Fourth Grade Studio: Learning, Thinking, Creating, you need to get there. Now. Here's a link to the first post in her fractions unit. Click here! Really, you need to! You won't be sorry.
While you're at it, visit her Teachers Pay Teachers store. In my opinion, her products are well-written and really make kids think. I love using her products, because they are so in line with my way of thinking - especially about math. I'm following her store, because I can't wait until she publishes her fractions unit. It's just that good.