Floating flagpole design challenge (Grade 2)

Grade: Two

Topic: Understanding matter and energy, properties of liquids and solids

Design challenge:

Students design, build and test a structure that involves interactions between solids (plastic) and liquids (water). Students will discover that a flagpole mounted on a plastic bottle will roll over on its side when placed in water. Faced with this problem, students will create a solution that will allow the flagpole to remain upright in the water. With the materials provided, students should arrive at (or be supported to find) a solution that will, either use sand as ballast in a single bottle, or a pontoon system using two bottles to solve the problem.

OCTE 2012 – Elementary Conference Workshops

floating flagpole examples


  • CSA approved safety glasses/goggles, one pair per person (parent volunteers included),
  • scissors, minimum one pair for every 2 projects (students may supply their own),
  • a tub, pail or basin to use as a water station for testing the floating flagpoles,
  • two or three funnels per class (opening should fit a water bottle top),
  • small scoops or measuring cups for transferring materials into the funnel.


  • 6" (15 cm) of tape per project (e.g., masking tape, duct tape, electric tape, etc.),
  • one piece of modeling clay (a ball that is about the diameter of your thumbnail) per project,
  • one straw per project (for the flagpole),
  • construction paper one small piece per project (to make a flag for the flagpole),
  • two elastic bands per project (they should be long enough to fit around and hold two plastic bottles together),
  • clean sand, about half a pail for one class,
  • send home a note in advance of this activity asking caregivers to collect and send in items from the list below;
  • 1 or two per project, small plastic bottles (rinsed, dried, and with caps).