You will need 7 buttons.

Finished Measurements:
Back width: 20(21, 21, 22.5, 24.5, 24.75) “ 50(52, 52, 56, 62, 62) cm
Total length: 35.5 (36.5, 37.5, 37.5, 38.5, 38.5) 89(91, 94, 97, 97) cm
Sleeve length to underarm: 17.25( 17.25, 17.5, 17.5, 18, 18)” 43(43, 44, 44, 45, ) cm

Yarn Required:
Rowan Brushed Fleece
Color 273 Rock - 9(9,10, 10, 11, 11) balls