This 56 slide PowerPoint presentation is all you need to ensure that your students not only know how to subtract with and without regrouping but that they understand WHY they are regrouping and how it works!
I use this presentation as a 9 day unit taking each method one day at a time. By the time students are ready for the test, they are equipped with four different methods for solving subtraction problems. They learn to draw out problems on a place value chart, to use the "old school" method with a new twist, and master 2 different strategies that take regrouping nightmares to a no regrouping dream!
Please check out my blog at http://tricksoftheteachingtrade.blogspot.com/2012/03/sinister-subtraction.html