1. You have the time and the ingredients, so go ahead and pull out your mixer and make a batch of homemade cookies with your favorite little helper.
2. You have a little time, but homemade cookies are not really your thing. Go buy some cookie dough from the dairy section of your grocery store and let your child help you cook a batch.
3. Not only are homemade cookies not your thing, but this is a really crazy busy week and there is not time to cook much of anything. In this case, pick up a bag of Chips Ahoy cookies and open them up. (That's what I did!)
Now, with a cookie in hand, each of you should take a small bite. Explain to your child that the cookie is like the sun and the bite out of it is like the moon. The moon is slowly beginning to come between the Earth and Sun casting a crescent-shaped shadow across the Sun. Compare your bites. Which one is bigger? That means the moon has moved farther on the path.
Each of you get another cookie and take a bit larger bite. Lay the cookies down next to the one before it and compare this "sun" to the other one.
Repeat the process until you only have a sliver left of the sun. Explain that the sun is almost totally covered by the moon.
When the sun is completely covered, that phase is called "Totality" and only lasts a couple of minutes before it moves to the other side and repeats the process in reverse. At this point, you could combine your half-eaten cookies to make an illustration of the complete path of the Moon across the face of the Sun.
The last time my grandsons were here, we tried this out with the Peanut Butter cracker sandwiches we'd fixed for lunch. He is only three, but we talked about the sun and how the moon was going to be covering it up. I showed him how to take a the little bites and he had lots of fun with it. He later asked me if we could make a "paper clip" with his juice pouch, too. I kept asking him to repeat it since I had no idea what he was talking about. Then I realized that he was calling the Eclipse a "paper clip", the only word he could remember that sounded familiar, most likely. :-)