This Problem Set is a part of the Lesson 2, Unit 1, Grade 3. In this lesson, students relate the equal groups of objects in scattered configurations to the array model, exploring the correspondence between 1 equal group and 1 row. They begin to distinguish between the number of groups and the size of groups as they count rows and how many in 1 row to write multiplication sentences, and they recognize the efficiency of arrays as they skip-count to find totals.