A 0.283-m-thick sheet of ice covers a lake. The air temperature at the ice surface is -17.7 °C. In 3.10 minutes, the ice thickens by a small amount. Assume that no heat flows from the ground below into the water and that the added ice is very thin compared to 0.283 m. Calculate the number of millimeters by which the ice thickens. Do not enter unit.