To begin the lesson, I show the students a flashlight and ask them to describe the way that the flashlight works and how it is useful to people. I list the students ideas on the board. It is my goal to have students identify the key features of a flashlight (including a switch, bulb, and power source).
I inform the students that their engineering challenge for the day is to create a model flashlight using their switch and lab materials.
Before allowing students to design and build their model flashlight, I review the flashlight lab record sheet with the whole class. I discuss the materials that the students will be able to use in their design. I also talk with them about the importance of planning a design, testing it, and making modifications in an orderly fashion. I encourage students to record their plans on their lab worksheet.
I then provide students with time to create a model flashlight. Students need to connect a complete circuit using their switch to create the flashlight. I purposefully do not provide a great deal of directions so that students can create a model design that reflects their knowledge and skill level. Many students will use a simple circuit in their model flashlight. I encourage those students to compare their model with that of a peer who used a series or parallel circuit. This often leads to students revising their models to make the bulb brighter.
Because this lesson is the final lesson of the unit, I close the lesson by having students review the chart that they created in the first lesson of the unit. I ask students to review the items that they listed both alone and with their partners. I ask them to highlight any facts that they proved through their lab work. I also ask students to cross out any information that they disproved through their lab work and research. I then encourage students to add their new knowledge to the chart with a different colored pen. This activity provides each student with the opportunity to clarify and revise their thinking about the topic of electricity.