cartoon animation

I make educational video. I want to make animations (very simple) frame by frame; maybe about 6fps.

I want to make the slides in Paint, put them in a folder and then drop the folder into the timeline.

I see that a folder can be dropped into the timeline, but it is 10 seconds per file. I want maybe 6 frames per file.

I am looking for a 'user preference' for the 10 seconds. I think I may have found it, but it does not work.

any ideas? [youtube (mrphysh)]