In this lesson, students are given a scale drawing and asked to recreate it at a different scale. They also examine how much area, on the actual object, is represented by 1 square unit on the scale drawing. For example, if the scale is 1 cm to 50 m, then 1 cm² represents , or 2,500 m².

Two possible strategies to reproduce a scale drawing at a different scale are:

• Calculating the actual lengths and then using the new scale to find lengths on the new scale drawing
• Relating the two scales and calculating the lengths for the new scale drawing using corresponding lengths on the given drawing

Throughout this lesson, students observe and explain structure (MP7), both when they reproduce a scale drawing at a different scale and when they study how the area of a scale drawing depends on the scale.

Today, students use sticky notes to document actions in the “Doing Math” sections of the Math Community Chart that they see or hear throughout the lesson. During the Lesson Synthesis, students share what they noticed, and then they suggest additions for the chart as part of the Cool-down. The work today continues to build a foundation for developing math community norms in a later exercise and is the start of students identifying strengths in the actions of their peers.