Rain Gauge (how to make one)
 

This is a bit of fun for children and the child in you, take a coke bottle cut it in 2 just above the label, pour in 100mls of water and mark it then put in another 100mls and mark it and so on, then invert the neck of the bottle into the body and put outside, and hey presto you have a rain gauge. Check it every 24 hours to see how much rain fell. Use the water it accumulates in like watering indoor plants etc.

very good ill try this with the kids,,