This Application Problem is a part of the Lesson 20, Unit 2, Grade 3. The Problem Set in this lesson is allotted 10 minutes. It directly follows the Application Problem, and so the 10 minutes are included within the 15 minutes allotted for the Application Problem. Millie's fish tank holds 403 liters of water. She empties out 185 liters of water to clean the tank. How many liters of water are left in the tank?