Kindergarten: Exploring Why Objects Sink or Float

In Kindergarten, students spend a lot of their time learning about how the world around them works. In a recent STEM Unit, students at Columbine did just that when they explored the characteristics that cause different objects to float or sink in water. Throughout the unit, students conducted several hands-on experiments to explore the impacts of weight, density, surface area, and absorption. Their experiments included:

• utilizing new balances, purchased with Race to the Top funds, to measure the weight of different objects

• testing various types of materials in order to examine absorption and which materials could float the best and longest  

• constructing boats of aluminum foil and clay to examine surface area and the impact it has on how much weight a boat can hold


After completing all of these experiments, students took all of their information about why objects sink or float and applied it to their design challenge. For this design challenge, students needed to create a raft that would support the weight of a large plastic ladybug. This ladybug needed to cross a puddle and keep his wings dry. Students selected prototyping materials that they thought would best solve the problem, combined them, and tested them. Each group took a different approach to their raft, but they all found that the best rafts included Styrofoam, had ample surface area to support the ladybug, and utilized tape to keep the parts of their raft together in the water. In the end, this unit allowed kindergarteners to explore, analyze, and manipulate materials to understand their characteristics and uses in our world.