I like schooltube.com because it had various ways for students to solve math problems. I also like that schooltube incorporated different videos from elementary to high school situations with songs and step by step approaches to solving math problems.
This video is step by step video that shows students how to do long division. The students do body signals and sing the steps divide, multiply, and last step subtract and repeat steps as needed until problem is solved. this is a great way for students to memorize how to solve long division.
I like the song, because besides talking about slopes the teacher also talked about dong your homework and being respectful to others.
What I learned about copyright and fair use is that own media, so you decide how to use it. And if you use someone else's video you should obtain permission and give credit to the parties involved.
At the moment I'm not sure how I would use dropbox in the classroom.