In West v. Holstrom (1968) 261 Cal. App. 2d 89, plaintiff sued for hauling defendant's lumber, defendant knew the quantity of lumber it had shipped, and the only disputed item was how much the wood weighed per board-foot. The court held that the weight of lumber per board-foot was as readily measurable as market value, so the defendant knew easily enough what it owed. ( Id. at p. 97.)