Place four pebbles on the sand in the form of a square. Keep adding as few pebbles as necessary to double the area. How many extra pebbles are added each time?
Investigate how this pattern of squares continues. You could
measure lengths, areas and angles.
Can you work out the area of the inner square and give an
explanation of how you did it?
You can move the 4 pieces of this jigsaw around and fit them into the outlines shown below. Try for yourself with this interactivity. One square unit is missing in the lower shape.
Explain what has happened to the missing area? (Of course muggles magic is not magic at all!)