Science · 20 minutes · 7–10 years

Sink, float, test again

Predict, observe and revise. Size alone is not the whole story.

All you need

Shallow bowl, a little water, steel spoon, large plastic lid, cloth.

Grown-up, read this first

Adult stays throughout. Very little water; no glass or small choking objects. Keep away from sockets, wipe spills and empty immediately.

Adapt to your child’s needs and stop if uncomfortable.

Let’s give it a go

Step ticks are temporary for this tab session. You can read every step without ticking.

A question to take with you

Does the bigger object always sink?

Talk it through or draw on paper. There is no answer box or personal information to submit.

Make it gentler

Compare just two objects by pointing.

Take it further

Try the lid flat and on its edge.