A mineral water plant near Namangan received an order for 1,000 bottles. The bottles are packed 24 to a carton, and the customer, a hotel chain, accepts only full cartons.
Bekzod, the packing supervisor, divided 1,000 by 24 in his head. Forty cartons hold 960 bottles, and one more carton makes 984. That left 16 bottles left over, not enough for another carton. He had two choices: send 984 bottles and explain the shortfall, or add 8 bottles from the next batch and send 42 full cartons. He called the hotel, and the purchasing manager agreed to take 1,008 bottles.
The second problem was the schedule. The hotel wanted a delivery every 9 days, and the first truck would leave on a Monday. The drivers do not work on Sundays, so Bekzod needed to know which day each delivery would fall on.
He did not open a calendar. Nine days is one week and two days, so each delivery moves two days later in the week: Monday, then Wednesday, then Friday, then Sunday. The fourth delivery fell on a Sunday, the drivers' day off. The fifth would come 36 days after the first, and 36 days is five weeks and one day, so it would fall on a Tuesday.
Bekzod moved the fourth delivery to Saturday and wrote a short note for the planning office: "Whenever a period is not a whole number of weeks, check the remainder before you promise a date."