This Problem Set is a part of the Lesson 7, Unit 4, Grade 2. In this lesson, students build upon their understanding of place-value strategies as they apply it to the addition algorithm. Students relate manipulatives to vertical form, recording compositions as new groups below. As they move the manipulatives, students use place-value language to express the action as they physically make a ten with 10 ones and exchange them for 1 ten.
