a contractor holds a clipboard while looking at stacks of wooden boards and cement bags. The contractor points at different material piles while counting them roughly in his head. A construction worker stands nearby holding measuring tools and nodding as they discuss quantities needed. The contractor makes quick mental calculations about how much material they'll need for the job. Other workers move equipment in the background while the planning continues. The supervisor approaches to review their approximate calculations before ordering more supplies. approximate calculations or judgments of the quantity and extent of materials needed