Sink or Float?
What You'll Need
- A large bowl, tub, or the kitchen sink filled with water
- 10–15 household objects to test — a mix of sinkers and floaters
- Good sinker ideas: a coin, a pebble, a metal spoon, a key
- Good floater ideas: a cork, a plastic toy, a leaf, a crayon, a feather
- Optional: two small bowls labelled "Sink" and "Float" for sorting after
- A towel for drying!
Let's Do It!
- Hold up each object one at a time and ask: "What do you think — will it sink or float?"
- Let your toddler drop it into the water and observe together.
- Celebrate both outcomes: "It floats! You were right!" and "It sank — wow, how fast!"
- Sort the tested objects into two groups: sinkers and floaters.
- Count each group: "How many floaters do we have?"
- Challenge round: can they make a floater sink? (Try pushing the leaf under!)
The Simple Science
- Objects that are less dense than water float — they weigh less for their size.
- Objects that are more dense than water sink — they're heavier for their size.
- Simple language for toddlers: "Heavy things often sink. Light things often float."
- The fun exception: a big ship floats because it's hollow and traps air inside!
What They'll Learn
💡 Parent Tip
Don't correct wrong predictions — let the water do the teaching! The surprise of being wrong is actually the best learning moment. Ask "Why do you think it did that?" after each test. Even toddlers can start forming simple theories, which is the beginning of scientific thinking.