First, find out all about the famous game called Pooh Sticks as thought up in Winnie-the-Pooh, by reading 'House at Pooh Corner' by A A Milne.

Now visit a small stream with a bridge over it. You MUST have a responsible adult with you.

You can use small sticks like Winnie-the-Pooh, or something else that floats, like dog biscuits (dog biscuits are environmentally friendly because they break up in the water and can be eaten by creatures in the water).

Drop all of the sticks or biscuits into the water at the same time, dropping some near the banks, and others near the center. Watch them to find out if the water flows fastest in the center or at the sides of the stream.