Sink-or-float laboratory: the washing-up bowl research team
Test a small set of suitable objects, compare predictions with observations and reshape foil into a simple boat, with an adult beside the water throughout.
Illustrative artwork from the game, rather than a photograph of a real outing or session.
Some objects head straight for the bottom while others float in a deeply smug manner. A shallow washing-up bowl is enough to start asking why. Gather a handful of safe, waterproof things, make a prediction and test them one at a time. Being surprised is part of the activity rather than evidence that someone has got science wrong.
Suggested for ages 2–7 with close adult support, this is practical noticing rather than a lesson to memorise. Younger children can point to a prediction picture and place a suitable object with help. Older children in the range can compare shapes or draw the results. Keep water play short, supervised and separate from any electrical equipment, with everything ready before filling the bowl.
A little planning before the fun
Time to allow
Allow about 60 minutes for choosing objects, testing, a boat challenge and drying up. The water-testing part may be only 15–20 minutes.
Budget notes
Use an existing bowl, safe household objects and a little foil. No new spending is required, and the laboratory has no need for a scientist costume to take its work seriously.
These are planning suggestions, not live prices or bookings. The shorter and longer versions give you room to adapt the activity to your day.
Tick off what you have gathered, or print a fresh checklist. Ticks are for this page only.
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A stable shallow bowl and a small amount of water
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A few large, safe waterproof objects an adult has checked
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A towel and tray for tested objects
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A small piece of kitchen foil for an adult-supported boat
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Paper and crayons for predictions and observations
Make it happen
1. Inspect the test collection
An adult selects objects without sharp edges, loose parts, batteries or damage from water. Try a large plastic spoon, a suitable toy boat or another familiar waterproof item. Keep unsuitable small objects away from younger children. Draw two prediction symbols on paper: one at the surface and one at the bottom, leaving space for surprising results.
2. Open the supervised laboratory
Set the bowl securely at a comfortable height and put towels within reach. Add only a shallow amount of water and have an adult remain beside it throughout. Keep other equipment prepared so nobody needs to leave. Explain that objects are placed gently in the bowl, and that drinking or splashing the experiment into somebody else’s face is outside the research brief.
3. Predict, place and watch
Choose one object and let everyone make a guess without correcting them. Place it gently in the water and observe what actually happens. Record a drawing or mark beside the prediction, then move the object to the towel. Repeat with a few items, taking turns. Use “what did you notice?” rather than asking children to produce an explanation before they have looked.
4. Change the shape of one material
With adult help, compare a loosely crumpled piece of foil with a broad, shallow foil boat. Test carefully and watch how the shapes behave. If the boat tips or fills, reshape it together and try again. Keep the conclusion modest: you have noticed a useful difference in this experiment, rather than proved a universal rule about everything made of metal.
5. Close the water department
Choose one result to draw and ask whether it matched the starting prediction. Let children describe a boat improvement for another day. The adult empties the bowl immediately, dries the area and stores containers safely. Count objects back to their places and wash hands. A wet towel may be your laboratory’s most substantial remaining piece of evidence.
Make it work for you
Ages 2–4
Use two or three large appropriate objects and very short turns with close adult supervision. Point to surface or bottom pictures and describe the result simply. Stop when attention wanders, then empty the bowl straight away.
Ages 5–7
Let children draw predictions and compare two shapes of the same foil. Encourage them to change one feature of a boat, such as its width, and describe what happened without making the activity a vocabulary test.
Dry observation role
Someone who dislikes wet hands can choose objects, point to prediction symbols or draw results while an adult does the placing. Position the bowl and sheet within comfortable view and reach, with no need to stand over it.
Before you begin
Young children need continuous close adult supervision around water, including shallow bowls. Prepare supplies first, avoid distractions and empty the bowl immediately afterwards. Keep water away from electricity and use only safe, age-appropriate objects.
Print this sheet, or draw surface and bottom symbols. An adult can write the children’s observations.
1. Object one / our prediction / what happened:
2. Object two / our prediction / what happened:
3. Object three / our prediction / what happened:
4. Foil shape one and its result:
5. Foil boat shape and its result:
6. One thing that surprised us:
7. Our next question, with the bowl now empty:
These prompts are included when you print the plan and checklist.
A prediction can be wrong and the experiment can still be excellent. That is a rather useful scientific perk.
How did your family get on?
Tell us which step helped, what needed explaining or what you would do differently. A small, specific suggestion is more useful than a gold star—though we do enjoy a gold star.
Your email app opens so you can choose what to send. Please leave out private details, children’s names and photographs of other people.
Let the envelopes choose your next adventure
Choose activities your family would enjoy and let a little mystery settle the final decision. The sample game lets you try it before creating your own board.
Prepared for Deal or Date · Updated 28 October 2026
These plans expand activities from our game catalogue. Text and illustrative artwork were prepared with AI assistance, then checked for catalogue accuracy, clear steps and practical variations before publication. They are suggestions to make your own, rather than accounts of personal trips or product tests.