When the "flipped" video links were uploaded here on my home computer they worked (Saturday).
Since then, I found out that the Mars video for homework is not working, yet the links are accurate and were checked prior to going live here.

Two reasons have been discovered:
"The author of this video does not allow playback on the iPad." (seems odd) - on my ipad
"The video has moved." - search engine
"Outdated version." - (pre-landing) - search engine

Please do not let your child Google the key words to find the video. It's embedded on different sites which do play on ipads, but the top three returns have inappropriate advertising on the side panels. Until a safe site can be recreated, please wait. ;)

A search is on and the new site URL will be posted here when located. Thank you for caring enough to ask and let me know. It's very good, so it will be worth the wait. ;)