How to orbit a moon around a planet which is orbiting a Sun

I'm in an intro to animation class right now and doing an explanatory video on how the moon & earth orbit around the sun and line up to create a solar eclipse.

I've managed to use a circular motion path to get the earth orbiting around the sun. I can also make the moon orbit the earth through the same method (circular motion guide). However, my problem now is trying to figure out how to get the moon to orbit around the earth AS its orbiting the sun without trying to manually track the earths orbit (the only way I can think of doing it right now, its just tedious).

I've attached a screenshot so you can see my orientation (its just a simple top down view).

Any suggestions will be greatly appreciated by this total newbie