This Problem Set is a part of the Lesson 11, Unit 5, Grade 2. In this lesson, students continue to deepen their conceptual understanding of addition within 1,000. They continue to move from concrete to pictorial representations as they draw chip models to represent addition within 1,000. Students use place-value language to express the action and physically exchange 10 ones for 1 ten and 10 tens for 1 hundred, if necessary.