Simple+Machines+3-5

Lesson Objectives By the end of this lesson, students should be able to:
 * Describe how simple machines help humans with work
 * Understand that simple machines can sometimes trade force for distance, as in the case of an inclined plane
 * Understand that simple machines can sometimes change the direction of a force, as in the case of a pulley
 * Use simple materials to create two simple machines



Engage: Activate Prior Knowledge; Generate Interest

Activate Prior Knowledge

Show students the short video segment [|What Is a Simple Machine?] This video gives a quick overview of the six types of simple machines, but does not offer any explanation about them. After the video, ask questions to gauge prior knowledge about simple machines: What do they know about the six types of machines mentioned in the video? Can they give any examples of simple machines? Create a KWL chart about simple machines to refer back to during the other lessons. Use their answers to help gauge their pre-existing knowledge about the lesson content.

Stimulate Interest

To spark interest in the lesson, hold up several common items that can be used as simple machines, such as a ruler, a screwdriver, and a rope, and tell students that they will learn how these items are all machines. They will be curious to learn how simple items can be considered machines.

Finally, post the essential questions that constitute what students will be learning. Students may read them or you may wish to read them aloud together.


 * How can simple machines affect work?
 * How can simple machines trade force for distance?

Explore: Allowing Students to Experience Content

 Divide the class into three groups. You should use your knowledge of the class to more or less divide the class according to reading ability. Provide students in the lowest reading group with the reading passage [|Let’s Play While We Work]. Provide students in the intermediate reading group with the reading passage [|A Fearful Weapon]**,** and students in the advanced reading group with the reading passage [|Work and Simple Machines]. Note that the last two reading passages are also available as eBook resources. Along with the passages, assign each group a question, which they will be responsible for answering and presenting to the class. The lower reading group will be  responsible for answering the question “How can simple machines affect work?” The intermediate group will answer the question “How can simple machines trade force for distance?” The advanced group will answer the question “How can simple machines change the direction of force?” Each assigned reading passage will help groups formulate an answer to their assigned question. After groups have read the passages and developed an answer, have groups select one or two volunteers to present their answer to the rest of the class. All students should take notes to help develop answers to all questions. You may wish to recap or summarize the main ideas from each reading to make sure students understand the concepts.

Have students complete the exploration, About [|Simple Machines]. Students should work in pairs to complete the student guide.



Next, assign for students to view or show the video segments [|Introduction to Simple Machines] and [|Pulleys]. The first video will help students answer the first two questions, and the second video will help students finalize their answer for the third essential question. After watching these two videos, they should know that simple machines make work seem easier, and that they can trade force for distance or change the direction of force. Be sure to answer any questions at this point in the lesson.

Explain: Firm Up Understanding; Allow Students to Explain What They Know

Instruct students to review the interactive glossary terms [|control], [|force], [|kinetic energy], [|lever], [|mechanical energy], [|power], [|pulley], [|screw], [|wedge], [|wheel], and [|work]. They should use these terms to do a self-check of their understanding of the lesson concept. If time allows, have students informally quiz each other on the definitions and contexts of all of the words



Have students complete the Hands-On Activity [|Simple Machines].



After students have completed the Hands-On Activity, bring the class back together as a large group, and have them discuss ways they use simple machines in their everyday life. As students share answers, encourage them to use the vocabulary from this lesson and their answers to the essential questions. Also encourage students to think critically about the value of simple machines. You might want to ask questions like, “What would life be like without simple machines?” This will get them thinking about the many ways simple machines help humans with work. Add any pertinent information to the KWL chart.

Elaborate: Allow Students to Apply What They Know

Instruct student pairs to spend a few minutes completing the Exploration [|The Wheel Deal]. In this Exploration, students must correctly order different simple machines. Not only does this activity get students thinking about different ways simple machines work, it also shows several real-life examples of simple machines. For example, many students would probably not think of a screwdriver as a simple machine, but this Exploration explains how it is indeed a simple machine. Allow pairs to discuss as they work, and circulate to answer any questions. Have students add any pertinent information to the KWL chart.



Project Ideas: To help your students apply their understanding of simple machines, you may wish to have your students complete some or all of the following projects. The time required to complete each project will vary; some may require students to work outside the classroom.
 * Instruct students to complete a simple machine scavenger hunt at home. They should search for simple machines that make work easier in each room of the house, and write a paragraph to explain one of the tools.
 * Have students conduct research on one of the simple machines and create an instruction manual to show the correct usage of that machine. Instruction manuals should have illustrations and written directions and should convey an understanding of the function of the machine and how it makes work easier.
 * Instruct students to identify a common task that they do on a regular basis that involves using a simple machines (opening a door, riding a bike, screwing in a screw, riding a skateboard up a ramp, etc). Tell students to try to perform the task without using a simple machine (and encourage them to keep safety at the forefront). Then, have students write a paragraph to explain the task, how difficult or easy it was without a simple machine, and why the simple machine is needed. Students can share these experiences with classmates.

Evaluate: Check for Understanding

Have students complete the Brief Constructed Response (BCR) item titled [|About Simple Machines]. You may also wish to assign the on-line concept assessment and use the results in the student reports to guide you in assigning any remediation to students.



Review Sheet: Students may review the information in this section using the [|About Simple Machines Review Sheet].