Sink or Float?
Guessing first, then looking. Things that are light for their size float; things that are heavy for their size sink.
How it plays
A thing is shown: a cork, a rock, an apple, a key, a ping-pong ball, a golf ball. Your child guesses Float or Sink with one of two big buttons, then it drops into a tank and floats or sinks. No guess is ever wrong: Ruby Roo says “Good guess! Let's see”, then what really happened. Four things, then five, then six.
What it's for
Guessing first, then looking. Things that are light for their size float; things that are heavy for their size sink. There is no score to lose and no way to fail: a wrong move is met with a gentle nudge, and a level ends when it's done.
Safety: Small, strong magnets are dangerous if swallowed: two can pull together inside the body. Use a big fridge magnet, together, and keep small magnets away from young children. If you think a child has swallowed a magnet, get urgent medical help. Water play is always with a grown-up. ACCC Product Safety Australia.
Away from the screen: Sink or float in the bath
About two minutes, with things most homes have.
- At bath time, gather a few things that are safe to get wet: a cork, a spoon, a leaf, an apple, a toy.
- Before each one goes in, your child guesses: float or sink?
- Drop it in and watch.
- Sort them into two piles: floaters and sinkers.
Three questions to ask while they play
- What do you think will happen?
- Were you surprised?
- What's the same about all the things that float?
Play together
Things to say or ask
- Good guess! Let's see.
- The golf ball and the ping-pong ball are the same size. Why does one sink?
Taking turns on one device: Take turns: one of you guesses, the other presses the button.
If they find it hard
The point is the guess, not getting it right. If they want to know the answer first, that's fine: let them watch a few, then guess the next one.
Every fact, and where it comes from
What Ruby Roo says in Sink or Float? was checked against the page it links to.
- Whether something floats depends on its density, how heavy it is for its size. A golf ball and a ping-pong ball are about the same size, but the golf ball is much denser, so it sinks. (Questacon)
- Questacon's floating and sinking activity starts the same way: feel each thing, predict float or sink, then put it in and watch. Sorting into 'sink' and 'float' afterwards, and asking what the floaters have in common, is the next step. (Questacon)
What it practises
- Sorting by two things. Putting things into groups by what they look like, then by two things at once: orange and round, small and pointy.
AC9MFSP01 (Mathematics, Foundation); AC9MFM01 (Mathematics, Foundation); EYLF 4.2 (Early Years Learning Framework V2.0) - Looking and finding. For two- and three-year-olds: looking for something hidden, and knowing it's still there when you can only see a bit of it.
EYLF 4.2 (Early Years Learning Framework V2.0)
The codes are from the Early Years Learning Framework V2.0 (for children from birth to five) and the Australian Curriculum v9 (Foundation to Year 2). Each links to the official wording. Every skill, and the games for it.
What it costs, and what we collect
Nothing, and nothing. There is no account, no advertising and no tracking of any kind. Which games have been played is remembered on your own device and is never sent anywhere. The full version is here, and it's short.
Where it lives
Sink or Float? is part of Science Lab. It works on a phone, a tablet or a classroom screen, and once it's been opened it keeps working with no signal at all.
Updated