Sink or Float

Explicit Instruction/Teacher modeling

• Have students guess which objects will sink and which will float.
• Tell students that lighter objects are more likely to stay on the surface of the water and heavier objects are more likely to sink to the bottom of the tub.
• Drop a couple objects into the water to show students how you would like them to place the objects, avoiding splashing, and showing them what you are looking for to determine whether the object floats or sinks.
• Make a "float" and a "sink" pile and put your objects in their corresponding pile.

Guided practise

• Place the students in groups, one for each work station. Review the rules for collaborative group conversations by creating a poster titled "Group Work."
  1. Listen to others carefully
  2. Speak one at a time
  3. Talk about the text or topic
• Have students give a thumbs up if they can agree to follow these rules for group discussions.
• Ask group members to test one object at a time, placing them into their own "float" and "sink" piles as they finish. Have group members then discuss in their groups which objects sank and which objects floated.
• As groups finish, go around and check their "sink" and "float" piles for correctness.
• Ask students to clean up any spills that may have happened, then to return to their seats.

Independent working time

• Discuss briefly some of the groups results. Allow volunteers to share some ideas with the whole class.
• Hand out the Sink or Float? and Buoyancy worksheets.
• Read out the definition of buoyancy from the Buoyancy worksheet. Ask students if they have any questions.
• Rotate around the classroom and assist struggling students.
• Have students turn in their worksheets when done.