Please help me with adding videos to my ipad

I am running ios 8 on an ipad air 2.

I added a folder containing 7 mp4 files to my itunes library.

Then I synced those 7 files to my ipad and confirmed the videos were on my ipad.

But then I decided I'd prefer to have them on a playlist so they are more organized, so I opened the Videos app on my ipad, tapped Edit, and manually deleted each one.

Now, when I go to the Movies folder of my device in itunes, the 7 videos are still listed there even though they aren't on my ipad. Why would this happen?

I've also tried syncing the playlist I created to my ipad, but nothing happens when I do. The playlist does not appear on my ipad when it's done. I don't know if it's because itunes thinks the videos are already on my ipad or what.

Please help!