Tear off 4 sheets of baking paper and place on flat trays or plates. Draw 10 different sized crosses on the sheets of paper: 22 cm (8 1/2″), 20 cm, 18 cm (7 1/2″), 16 cm (6″), 14 cm (5″), 12 cm (4″), 10 cm (3″), 8 cm (2″), 6 cm, 4 cm. Turn the paper over so the marks are face down.