Description: Guided practice with strategies for problem solving is built into Lessons 1 and 2. These lessons emphasize the use of modeling through the RDW process and revisit models such as tape diagrams and number bonds. Students flexibly use a letter to represent the unknown as they solve. This readies them for problem solving with perimeter and area in Topics C and E. In Lesson 3, students' level of independence within the lesson increases. They work together or on their own to develop solution paths, and then share strategies and solutions. Students think critically about their own solutions and the work of others as they review and critique one another's work.*Teacher Advisor is 100% free.