The children also tested the materials to see which were waterproof. We discussed how to make the test fair and decided to use one syringe of water for each sample. You can get plastic syringes from the chemist.
We used food colouring to make it easier to see the water. The materials were stretched across a jar and held in place with an elastic band. Any water seeping through the material could be seen dripping into the jar. A baking tray collected all the spills.
|L adds water to some sponge.|
|R tests metal to see if it is waterproof.|