1) Students start school with experiences from the beach or swimming pool to share with classmates, generating questions about the purpose of floatation devices.
2) They discuss what they did over summer vacation, with some students explaining they know how to swim and don't need floaties or life jackets.
3) To understand floatation, students experiment by seeing what sinks and floats in the classroom, discovering objects with air inside float while heavy or porous things sink.