Hopefully you saw the pre planning for this activity yesterday. Otherwise, you will need to do some freezing before you can complete this activity... its worth it though, it's good one!

You will need: A bowl, some paint or food colouring, water.
Mix the water and colouring together. Add it to the bowl and freeze.

Next you will need: salt (plenty) and water. A pipette is useful, but not essential.
Take the frozen coloured water out of the freezer. Turn it out of the bowl, so you just have the ice. Pop it into the garden or onto a tray (it's going to melt!). Ask your child(ren) to rub salt onto the top of the ice block. Use the pipette to ad small amounts of water to help the salt melt the ice. If you don't have a pippette, wet hands and rub water over the ice. Now leave for a few minutes (if its a hot day, 5 minutes will be fine, for a cold day, 15 is ideal).

Revisit the ice. Hold the block up to the sky/sunshine. What can you see?
Note: you should see the salt has made tunnels/ravines in the ice. You might want to discuss how/why this happened (salt lowers the freezing temperature of the water, so melts the ice).