You will need

V Neck Cardigan
24/26in Chest - 4 Balls
28/30in Chest - 6 Balls
32/34in Chest - 7 Balls
36/38in Chest - 8 Balls
40/42in Chest - 9 Balls
44/46in Chest - 11 Balls

Round Neck Cardigan
24/26in Chest - 4 Balls
28/30in Chest - 6 Balls
32/34in Chest - 7 Balls
36/38in Chest - 8 Balls
40/42in Chest - 9 Balls
44/46in Chest - 11 Balls

3.25mm and 4mm Needles
6 (6 : 7 : 8 : 9 : 9) Buttons for V Neck Cardigan
7 (8 : 9 : 9 : 9 : 10) Buttons for Round Neck Cardigan