Swimming Pool Scientists
If your child visits a pool or a beach this summer, she may start to question why some objects sink and some objects float. Children also wonder why it feels easier to float in salt water than in fresh water. When these questions come up, it is a great opportunity to encourage budding scientists to use inquiry to explore their worlds.
The idea behind inquiry-based learning is to encourage asking questions and finding ways to test possible answers to those questions; it is a child-appropriate gateway to the scientific method. The role of the adult in inquiry-based learning is as a facilitator. If you can encourage children to ask questions, you already have one of the most important skills that you will need. You can be a very effective science teacher without being the sage who has all of the answers.
Step one: Ask questions
Engage your child in asking questions about sinking and floating. What did she notice while at the pool? What would she like to find out? Join in the process of asking questions aloud yourself. Making statements that start with “I wonder…” can be a great way to keep the conversation going.
Step two: Demonstrations and predictions
Gather up some objects that will sink and others that will float. With your child make predictions about what will happen before dropping them into water (the sink, a bucket, a wading pool) and observing the result. For older children, it can be interesting to show how objects that have similar characteristics might behave differently in water. For example, show how a metal spoon will sink but a metal mixing bowl will float. Watch as the full bottle of sunscreen sinks and the empty bottle floats. Compare objects that have similar weights but different buoyancies.
Step three: More questions
Ask your child what she thinks the difference or differences are between objects that sink and objects that float. Remember that the goal is to be a curious scientist, not a person with all of the right answers. Encourage further testing. Encourage any process that your child wants to use to categorize objects.
Step four: Making sense
Help your child to make reasonable conclusions based on what she observed. These conclusions will vary by the child’s age and developmental level. Younger children do not need to understand buoyant force, density, or displacement. With help they can understand that something sinks if it is heavy for its size. They may also observe that objects that contain air or a hollow space tend to float. You can help children understand that this empty space helps the object to be light for its size. Older children may be ready to think about their observations in terms of forces. They may also be interested in calculating density or displacement. If you feel that you are having trouble explaining the science behind what your child has observed, this is a great opportunity to model how curious learners often look up information. Continue your scientific exploration together at the library or online.
Step five: Keep asking questions
The best possible outcome after an inquiry activity is to be more curious and motivated to explore the world. Find out if there is something your child wants to test next. “I wonder if objects that sank in fresh water will float in salt water?” or “I wonder what will dissolve in water?” might be good follow-up questions to investigate. While there may be a few more puddles on your kitchen floor, you may also have a junior scientist in your home.