This photograph was taken in India and shows a wooden screen placed across a window. There are many beautiful designs decorating windows, walls, floors and ceilings in buildings in India.
Try copying this design onto some grid paper turned around a quarter turn, like in the picture below. Here are the first few steps to get you started - or maybe you can see a different way to do it.
Can you complete the design? Try making up your own now.
Place the numbers 1, 2, 3,..., 9 one on each square of a 3 by 3 grid so that all the rows and columns add up to a prime number. How many different solutions can you find?