Curiosity Lab · Sink & float

Sink or Float

Your child chooses which of two pictured things floats or sinks, or drags pictures into a Floats basket and a Sinks basket. In other rounds a picture drops into an on-screen tank of water: your child makes a guess, watches, then says what happened. Only that last answer counts; the guess is never marked.

Play Sink or Float free Ages 2–6

Free for every family until 20 November 2026Every game and level. No card needed.

Which things float, and which things sink?

Two baskets, Floats on top and Sinks down, and a key, a leaf, a duck and a stone to sort.
A real screen from the game’s first level.

What it practises

  • Predict whether pictured things float or sink
  • Sort floaters and sinkers into two baskets
  • Notice how material, shape and trapped air matter
  • Choose to have a grown-up there for water play

How the levels grow

  1. Seed Level 1
  2. Sprout Level 2
  3. Bloom Level 3
  4. Flourish Level 4
  5. Shine Level 5

Both age bands get the same questions; the level decides which bank is used. Level 1 asks which of two pictures floats or sinks, sorts four things into baskets and asks who should be there for water play. Level 2 mostly drops one picture into the tank after a guess: an apple, a stone, a dry sponge, a metal bolt, a wooden pencil or a coin. Level 3 brings the surprises: a big log and a tiny paperclip, an empty and a full bottle, clay shaped into a boat, a metal ship and a six-picture sort. Levels 4–5 reuse the level 3 bank. Levels 1–3 give five questions; levels 4–5 give six.

Ages 2–4 play on the Pre-Nursery path and ages 4–6 on the Kindergarten path. Good play climbs a level; a hard day holds it, and a level earned is never taken away.

What you might notice

  • Does your child change their idea after watching a picture float or sink?
  • Do they think heavy things always sink? Level 3 questions challenge that idea.
  • After a wrong basket, do they listen to the spoken reason and try again?

Try it at home

Stay beside your child the whole time. Put a little water in a plastic bowl and test a few large things: a metal spoon, a plastic lid, a dry sponge and a leaf. Guess first, drop each one in, then talk about what happened. Squeeze the sponge underwater and test it again. Empty the bowl when you finish.

Not in this game: The game uses pictures only, so it does not practise weighing or measuring real objects.

Home-learning units that use it

KG 2
Materials and Water
Ready for Class 1
Materials and Magnets

More in Curiosity Lab

  • An apple hanging on a tree, and two answers: It falls down and It stays up.

    Gravity Drop

    Predict and identify falling or supported objects

    Ages 4–6

  • Two baskets, Usually hot and Usually cold, and a hot drink, a pot of stew, an ice cube and a snowman to sort.

    Hot & Cold Lab

    Use hot, warm, cool and cold in pictured examples

    Ages 2–6

  • Two cards: the rock and the sunflower.

    Living World

    Distinguish pictured living and non-living examples

    Ages 2–6

  • Two cards: balloons and clouds.

    Weather Watch

    Recognise weather words and pictured clues

    Ages 2–6

  • A strawberry, and two answers: your tongue and your ears.

    Five Senses

    Match eyes, ears, nose, tongue and skin to their jobs

    Ages 2–6

Where to start in Curiosity Lab See all 44 games

Every game is free until 20 November 2026.

Sink or Float and the other 43 games, every level, with no card and no payment.

Play Sink or Float free