Lang Yarns Celeste multicolored knitting yarn is a white cotton yarn wrapped with colored polyester composed of 80% cotton and 20% polyester. It knits on knitting needles 3 and 3.5 mm (US -4 / UK 11-) for a gauge of 25 stitches and 33 rows.
In a 50 gram (1.75 oz) ball there are about 200 meters (218 yd) so for a sweater for women size M plan on:
500g = 10 balls for men size M
350g = 7 balls for women size M
250g = 5 balls for children 10 yrs old.
Machine wash at 30°C (86°F) with gentle detergent for wool without softener.