My Youtube Pick for Ratio and Proportions

http://www.youtube.com/watch?v=HpdMJaKaXXc&feature=related

I choose the video above that introduces ratios. This clip does a good job of introducing explaining ratios. The presenter does make one mistake in his presentation which is corrected. I think one of the major advantages of this video is that the students have a better have chance of getting a full explanation of a concept with less chance of being interrupted by their peers. This video allows the teacher to easily transition into the next phase in the lesson.