Just found this really cool website on Pinterest for math and science called Study Jams. It goes through a bunch of different aspects of both math and science including a video for how to explain place values and different videos in a section for scientific inquiry. There are multiple big sections for both math and science and then those bigger sections are split up into smaller subjects and each subject has a video to explain it and even a test to test yourself on what you just watched. It does seem to be a little more advanced in some areas and so I would say that it is for higher elementary grades or even middle school.
http://studyjams.scholastic.com/studyjams/index.htm