Worked in one piece to armholes

Measurements
To fit chest
40, 46, 51, 56 cm (16 18, 20, 22 in)
Sleeve seam
12.5, 14, 16.5, 19 cm (5, 5½, 6½, 7½ in)
Length from back neck
23, 25.5, 28, 30.5 cm (9, 10, 11, 12 in)

Each source has a different set of recommended yarns. The following is from the King Cole version.

Materials
Big Value DK
1, 1, 2, 2 100 gram balls
Anti-Tickle DK
3, 3, 3, 4 50 gram balls
Big Value Baby DK
1, 2, 2, 2 100 gram balls
Anti-Tickle Baby Wool DK
3, 3, 3, 4 50 gram balls
Stitch holders
3, 4, 4, 4 buttons.