1. Use the instructional model to show students where they are in the course of the unit. Show slide 2 of the 2.1 Powers of Ten PPT 2. Introduce students to the Powers of Ten. Explain to students that they will watch a short film looking at how the same location can have many different systems at different scales: Post the Powers of Ten 11 x 17 Poster on a wall in your classroom where all students can see it. Alternatively, project the 2.1 Powers of Ten PPT Lead a whole class discussion about the poster to help students become familiar with its key features. Here are suggested questions: Ask students to identify words that are familiar to them. Ask for students’ interpretations of the four benchmark scales across the top of the poster: atomic-molecular, microscopic, macroscopic, large scale. Ask students about what each scale means: “What does macroscopic mean?” (It means the size of things we can see easily around us). Have students offer examples of objects that go in each scale. Ask for students’ interpretations of the units of length in the ovals at the bottom. Ask students what they can measure with those units and have students give examples of distances around that size. Point out that the numbers on the bottom use exponents—Powers of Ten—to give sizes in meters. Explain that the video they will watch will show them what this means 3. Watch the Powers of Ten video. Before they watch, divide students into four groups, one for each scale on the poster. As they watch the video, have each group note a different system or object from their designated scale. Watch the Powers of Ten video which lasts about 10 minutes. Accommodation: Stop the video periodically to allow students to discuss their notes with their group and/or ask questions. 4. Have students discuss the video. Have students share their observations of the video. Ask student groups to report the systems they saw in the video at each of the four benchmark scales. Tell students that all systems are like the picnic in the video: they exist and can be explained at multiple scales. For example, explain that in order to understand what happens when ethanol burns, they will need to focus on two of the benchmark scales: the macroscopic and atomic-molecular scales. 5. Compare water and ethanol at the atomic-molecular scale. Ask students for their ideas about what water and ethanol might look like at the atomic molecular scale. See whether students’ responses illustrate a familiarity with the molecular formula for water: H_{2}O. Tell students that by the end of the unit they will investigate ethanol and a flame at the atomic-molecular scale. 6. Have a discussion to complete the Learning Tracking Tool for this activity. Show slide 5 of the 2.1 Powers of Ten PPT. Pass out a Learning Tracking Tool for Systems and Scale to each student. Explain that students will add to the tool after activities to keep track of what they have figured out that will help them to answer the unit driving question. Have students write the activity name in the first column, "Powers of Ten." Have a class discussion about what students figured out during the activity that will help them in answering the unit driving question, "what happens when ethanol burns?" When you come to consensus as a class, have students record the answer in the second column of the tool. Have a class discussion about what students are wondering now that will help them move towards answering the unit driving question. Have students record the questions in the third column of the tool. Have students keep their Learning Tracking Tool for future activities. Example Learning Tracking Tool Activity What We Figured Out What We are Asking Now 2.1 Powers of Ten We can explore and learn about the world at different scales ranging from large scale to atomic-molecular scale. How do atoms behave at the atomic-molecular scale? 7. Have students complete an exit ticket. Show slide 6 of the 2.1 Powers of Ten PPT. Conclusions: Why do scientists consider things and multiple scales? Predictions: What molecules would you expect to find in a drop of water? On a sheet of paper or a sticky note, have students individually answer the exit ticket questions. Depending on time, you may have students answer both questions, assign students to answer a particular question, or let students choose one question to answer. Collect and review the answers. The conclusions question will provide you with information about what your students are taking away from the activity. Student answers to the conclusions question can be used on the Driving Questions Board (if you are using one). The predictions question allows students to begin thinking about the next activity and allows you to assess their current ideas as you prepare for the next activity. Student answers to the predictions question can be used as a lead in to the next activity.