Steve Demme, of Math-U-See fame, is my dude.  I tried several other curricula and this saved me (and my daughter and all those tears she was shedding during math class).  Often we'd have to stop school for the day because she and I were so frazzled with her lack of understanding.

That's all I have to say...Math-U-See. (click the graphic above to be taken to the site)

 
These are some pictures of Decimal Street I made on a manila file folder and had laminated - oh, and my lovely children, aged 6 & 4 in the pictures.
  Direction for an extended version of this are on my blog.

The kids really like doing their school orally - We're still practicing...but below is a practice session of skip counting - (the kids are 10,7 & 5 in the video)

We also created our own Play Money.  Click the link to go to that page.