5th grade - 5th graders took on the Marshmallow Challenge. Spaghetti, tape, and string are used to build the largest tower that will support a large marshmallow. Thanks to a TED Talk an this website, you have all the info you need to try it.
http://marshmallowchallenge.com/Welcome.html
http://sciencegal-sciencegal.blogspot.ca/2012/09/setting-expectations-for-group-work.html
http://www.anderson.k12.ky.us/Downloads/Save%20Fred2.pdf