lab is room.
Weight is a kind of value. 10lb specifies a weight.
Things have a weight.
the verb to weigh means the weight property.
box is a container in lab. box weighs 6lb.
the toy is in box. toy weighs 2lb.
the watermelon is in box. watermelon weighs 5lb.
To decide what weight is the laden weight of (T - thing): [see WWI 15.17 Totals]
decide on total weight of things enclosed by T plus weight of T.
when play begins: say laden weight of box.