Using an iPad app called Educreations, I have taken on a "flipped classroom" in Math.
Here is a video on Sales Tax and Tips that I created:
http://www.educreations.com/lesson/view/06-06-sales-tax-and-tips/4902286/
For more videos, please visit the following link:
https://sites.google.com/site/mraubreysfifthgrade/extra-credit
Source: Educreations, Google