It's a challenge for any age group, and children can also find something out about the brain.
Use a computer to draw a star shape, then draw another star shape around it, leaving a gap of about one centimetre between the two lines.
Size them so that you can fit three on an A4 piece of paper and hand out the sheets to the children. Ask them to draw around the smaller star shape, making sure they keep between the two printed outlines. Most of them will probably find this very easy. Ask them to think about what would happen if they tried to draw around the shape by looking in a mirror.
Next set up a number of mirrors. The easiest ones to use are the hinged kind, which you can tilt forwards, but any flat mirror will do, as long as it can be positioned so you can see the whole star shape when it is placed on the desk in front of it.
Ask each pupil to repeat the exercise, but this time looking only in the mirror. Mark the top of the star shape so you can remember which way round the star was when you did the experiment.
To prevent students looking at their drawing hand, set up a screen by placing a piece of cardboard across two piles of books, positioned so the child's hand can pass underneath it, but it does not obstruct the mirror.
Drawing around the star is now quite difficult. Once they have finished, ask them to look at their paper and find the places where it was most difficult.
These show the times when the brain was confused. The reflection in the mirror conflicts with the movement of the hand, and the brain struggles to adapt.
However, if pupils repeat the exercise several times, perhaps using different-coloured pens on the same shape, the brain is quickly able to adapt and their results should improve.
* Sophie Duncan is project manager for science at the BBC www.bbc.co.uksn