These audio files will help you to learn where your strings are relative to each other, so that you do not have to look at your mandolin while you play, and can focus instead on music. If you think these are easy, then you are doing them wrong! Please pay attention to the pick direction specified in your instructions. If there is a "V" over a note, that means to pick "up". If there is a bracket over a note, that means to pick "down".
Before we get in to Exercise #6 and #7, I'll remind you again - PLEASE pay attention to your pick direction. On these exercises especially, the tendency is to pick all in one direction because that's the way your hand is moving. These are the hardest ones of all, so, if you think they're easy, you must be doing them wrong!
If you can master these exercises, you will probably find that you will be able to play your mandolin without looking at it at all!