The work of this lesson connects to previous work because students have seen a variety of ways to represent and solve problems in which one of the factors is a teen number. In this lesson, students use their choice of strategy and representation to solve these types of problems. Students also participate in a Gallery Walk to compare and contrast different ways that they solved one of the problems.

Three parts of the lesson focus on area diagrams. In the Warm-up, students’ attention is drawn to scaling of area diagrams. In the Synthesis for the second activity, students analyze how area diagrams were used to represent one of the problems they solved. In the Lesson Synthesis, students discuss the advantages and disadvantages of different area diagrams. While it’s not important that student representations are exact, it is important that any area diagrams presented to students are to scale.