Help with Scientific Variables

Watch this video:

http://goanimate.com/videos/0UbugsH85CJA

For some reason, teachers like to sing. Check out this guy:

http://www1.teachertube.com/viewVideo.php?video_id=152952


Try this quiz:
http://www.quia.com/pop/184568.html

Practice with this:

http://www.proprofs.com/quiz-school/story.php?title=identifying-independent-variables

And finally:
http://www.biologycorner.com/quiz/qz_scientific_method.html

Let me know if you need more help.
Ms. Weatherhead