Subject: Science - Simple Machines
1. Topic-
Simple Machines - Levers
2. Content-
Levers: First, second and third class
3. Goals: Aims/Outcomes-
1. Investigate the nature of things, demonstrating purposeful action that leads to inferences supported by observations.
2. Demonstrate a practical understanding of levers by constructing devices in which energy is transferred to produce motion.
3. Predict how changes in size of a lever or the position of the fulcrum will affect the forces and movements involved.
4. Demonstrate ways to use a lever that applies a small force to produce a large force, and applies a small movement to produce a large movement.
4. Objectives-
1. Students will construct a third class lever in the form of a catapult.
2. Students will test their catapult and make goals regarding its performance.
3. Students will use prior knowledge to make adjustments to the fulcrum in relation to effort and load to achieve performance goals.
5. Materials and Aids-
Notebook file with medieval catapult image
Catapult building handout (attached)
Experiment reporting sheet (attached)
Catapult materials (per student):
1 small milk carton
1 toothpick
2 unsharpened pencils
Elastics (varying sizes for choice)
6. Procedures/Methods-

A. Introduction-

1. Access of prior knowledge regarding catapults.
2. Review of students knowledge of types of classes of levers.
3. Review of students knowledge of fulcrum, lever and effort.
4. Identification of catapult as a third-class lever.
5. Discussion on how the catapult works based on knowledge of third-class levers.

B. Development-

1. Review of materials and instructions.
2. Review of expectations for that time period: completion of building, not testing, setting goals or modifying.

C. Practice-

Building of catapult

D. Independent Practice-

1. Testing of catapult
2. Performance goal making
3. Modifying of catapult
4. Journalling of progress
5. Completion of Experimental reporting sheet

E. Accommodations (Differentiated Instruction)-

1. Written and picture instructions
2. Options for recording experimental process in pictures or words (where applicable)
3. EA and teacher support

F. Checking for understanding-

1. Journalling - did the student take a systematic approach to increasing the catapults performance or a random approach with no use of prior knowledge?
2. Interviews - is the student able to correctly identify the different parts of their catapult and talk about how the work together?

G. Closure-

1. This lesson is ongoing as the building stage was incomplete during the observed lesson. Expected time of completion is 3, 45-minute lessons.
2. For the initial lesson, a student who was successful in building their catapult demonstrated it and talked about goals they may have for increasing its performance.
7. Evaluation-
1. Anecdotal notes during building
2. Completion of Experiment reporting sheet
3. Journalling
8. Teacher Reflection-
The initial lesson of catapults felt very successful, with a great deal of enthusiasm from the students for building.

It was interesting to see which students, even with both written and pictorial instructions, and the availability of support from myself and an EA, still approached the building project with an "I know what I'm doing" mentality. These students consequently were encouraged to problem solve on their own using the materials they had.

Some surprising strengths in the class for building and manipulating, and an equal number of surprising students who lacked these skills and required a lot of support.

This Lesson Plan is available at (