This is a hands-on activity/experiment to an introduction to gravity. I use this in my space unit for Science. It's only 3 materials so it's very convenient and the kids just love it. I wrote the instructions in a step-by-step format so the students can either do it independently or in groups. (I do groups of 5.) Or you can read the steps aloud and walk them through it to differentiate. There are 2 open-response questions for students to answer. I also take pictures of them doing it for the parents to see. Lots of fun!