Sink or Float
A basin, ten household objects, and the first real science question: what will happen?
Sink or Float is a Montessori activity for a child aged 2 to 3 years. Area: Science and Nature. Time: 10-15 min.
What the activity builds
Make a prediction, test it right away, and discover that some objects stay on top of water and others don't.
The materials
- A clear basin, filled two-thirds with water
- Eight to ten household objects: a cork, a metal spoon, a sponge, a rock, a pen cap, a piece of wood, a coin
- Two small bowls, one for what floats, one for what sinks
- A towel under the basin
How to do it, step by step
- Line the objects up in front of the basin, with the two bowls on either side.
- Pick up the first object, hold it above the water, look at your child, then let go.
- Watch together, without commenting, then take the object out and set it in the right bowl.
- Do a second object the same way, then slide the row toward them.
- Let them test all the rest, in whatever order they want.
- At the end, look at the two bowls side by side, and name it: "these float, these sink."
The parent's role
Show once, then step back. Never say ahead of time what's going to happen, that would drain all the interest out of the activity. The control of error is in the water itself: it answers on its own, right away, and its answer is the same for you and for them. Don't correct a wrongly sorted object, just run the test again.
Safety
A basin of water calls for constant, uninterrupted presence, even with just a little in it. Set aside anything smaller than a toilet paper tube, along with coins if your child still puts things in their mouth. Empty the basin as soon as the activity is over.
You remain the sole judge of what is right for your child. These activities are offered for educational and recreational purposes: they do not replace medical advice or the guidance of an early childhood professional.
Ways to adapt the activity
- Easier: just four objects, two that float and two that sink, very different from each other.
- Harder: ask them to point to the bowl before you let go of the object, then check.
- Extension: a whole apple floats, cut into pieces it still floats, give it a try.
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