Simple Machines: Can You Design
a Way to Lift and Move a 200Pound Elephant?
We have been learning about how simple machines make work
easier. Now you will attempt something that may sound
impossible! You will design a way to lift and move a 200-pound
elephant across the gymnasium, using simple machines. Draw
and label the picture of your design and explain how it works.
Simple Machines: Can You Design a Way to Lift and Move a 200-Pound Elephant?
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Simple Machines: Can You Design a Way to Lift and Move
a 200-Pound Elephant?
Suggested Grade Span
3–5
Task
We have been learning about how simple machines make work easier. Now you will attempt
something that may sound impossible! You will design a way to lift and move a 200-pound
elephant across the gymnasium, using simple machines. Draw and label the picture of your
design and explain how it works.
Big Ideas and Unifying Concepts
Cause and effect
Design
Models
Systems
Physical Science Concepts
Motion and forces
Transfer and transformation of energy
Design Technology Concept
Use of tools
Mathematics Concept
Diagrams
Time Required for the Task
45 minutes.
Context
This task was part of a final assessment given to third graders at the end of a unit on simple
machines. It was a constructed-response item that asked students to apply their knowledge of
simple machines to design a system that would lift and move an elephant. It was developed as
Simple Machines: Can You Design a Way to Lift and Move a 200-Pound Elephant?
Copyright 2007, Exemplars, Inc. All rights reserved.
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a means to assess what students know about lifting and moving objects as well as about the
use of simple machines to make work easier. During the course of the unit, students
investigated each of the six simple machines: lever, inclined plane, wheel and axle, screw,
wedge, and pulley. Students learned how energy is needed to do work and that work is defined
as moving an object to a new location. Through a variety of investigations, students also
explored the forces of motion: inertia, gravity, friction, and push and pull.
Throughout this unit, students also practiced the following science process skills: developing
testable questions; making predictions; problem solving; designing and conducting
investigations; controlling variables; collecting, recording, and analyzing data; drawing
conclusions; and communicating results.
What the Task Accomplishes
This task is designed to assess students’ knowledge and conceptual understanding of simple
machines and the work they do and to apply these to a problem-solving situation.
How the Student Will Investigate
This particular task does not ask students to perform an actual investigation. Rather, students
need to apply their understanding and knowledge of simple machines to solve a problem.
Students will need to decide which simple machines they will use to lift and move the elephant.
Next, they draw a detailed and labeled picture of their system and explain in words how it works.
Interdisciplinary Links and Extensions
Math
During the unit, students used tools such as spring scales to measure work and effort. They
also weighed and measured items to move as well as distances traveled.
Movement
Students can create a human machine by having each student stand in a line across the room.
Give the first student a heavy book or another heavy object. Each student must perform a
different movement to pass the book along the line until it gets to the end. Try doing it to music,
keeping the rhythm with the machine’s movements.
Language Arts
Students can write and illustrate big books about the six simple machines and how they are
used in everyday life. Have students research inventions and inventors. Some good children’s
books about simple machines and inventions include:
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Machines at Work, by Byron Barton
The Way Things Work, by David Macauley
Making Things Move, by Neil Ardley
Stories Behind Everyday Things, by Jane Polley and Peter Chaitin
Inventor’s Workshop, by Alan J. McCormick.
Simple Machines: Can You Design a Way to Lift and Move a 200-Pound Elephant?
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Teaching Tips and Guiding Questions
Here are some possible guiding questions to ask students:
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What machines might work to solve this problem?
What would make lifting the elephant easier?
What would make moving the elephant easier?
What things have you seen before that might help with this problem?
How will you draw your idea?
How will you describe your idea?
Why do you think your idea will work?
Concepts to be Assessed
(Unifying concepts/big ideas and science concepts to be assessed using the Science
Exemplars Rubric under the criterion: Science Concepts and Related Content)
Scientific Method: Students observe and explain cause-effect relationships, with some
justification, using data and prior knowledge. Students see that how a model works after
changes are made to it may suggest how the real thing would work if the same thing were done
to it, and that choosing a useful model (not too simple/not too complex) to explore concepts
encourages insightful and creative thinking in science, mathematics and engineering (models).
Physical Science – Transfer and Transformation of Energy: Students observe that simple
machines enable us to move an object from one location to another and that simple machines
can make work easier.
Physical Science – Motion and Forces: Students observe and compare physical properties of
matter and see that an unbalanced force acting on an object changes its speed or path of
motion or both.
Design Technology – Use of Tools: Students observe that tools are invented to extend the
ability of people (to make things, to move things, to shape materials).
Mathematics: Students use diagrams appropriately.
Skills to be Developed
(Science process skills to be assessed using the Science Exemplars Rubric under the criteria:
Scientific Procedures and Reasoning Strategies, and Scientific Communication Using Data)
Scientific Method: Predicting/hypothesizing, designing investigations, making scientific
drawings, proposing and explaining solutions and raising new questions.
Simple Machines: Can You Design a Way to Lift and Move a 200-Pound Elephant?
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Other Science Standards and Concepts Addressed
Scientific Method: Students describe, predict, investigate and explain phenomena in the
physical world.
Scientific Theory: Students look for evidence that explains why things happen and modify
explanations when new observations are made.
The Designed World: Students observe that tools extend the ability of people (to make things,
to move things, to shape materials) and that manufacturing requires a series of steps and,
depending on the task, careful choice of materials (based on their characteristics).
Physical Science – Motion and Forces: Students see that forces such as push and pull enable
objects to move or stop and that friction affects the motion of an object.
Physical Science – Transfer and Transformation of Energy: Students see that energy is
needed to do work and that there are two types of energy: potential and kinetic.
Suggested Materials
For this particular task, students will need only the assessment sheet and their pencils.
Possible Solutions
A correct solution will include a system of simple machines to first lift and then move the
elephant. There should be a detailed and labeled drawing of the idea and a clear explanation.
Task-Specific Assessment Notes
Novice
A drawing of the system, using two inclined planes, is included with some detail and labels. An
explanation is started but does not adequately describe how this idea will work and only
describes the lifting and not the moving of the elephant across the gymnasium. The student has
some knowledge about simple machines but has some difficulty transferring that to solve this
problem.
Apprentice
A drawing of the system, using two inclined planes, is included with some detail and labels. An
explanation is included but does not completely describe how using this system of inclined
planes makes it easier to lift and move an elephant across the gym. There is no explanation
regarding how the student will get the elephant to walk across the inclined planes. The student
has some knowledge about simple machines and appropriate materials needed (steel) but has
some difficulty transferring that to solve this problem.
Simple Machines: Can You Design a Way to Lift and Move a 200-Pound Elephant?
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Practitioner
A detailed, labeled drawing of the idea is included. The picture clearly shows how the elephant
can be moved across the gymnasium, using a wheel and axle. An explanation is included that
describes how the elephant will be moved across the gym and where the force will come from;
however, it does not explain how the elephant will get on the board with the wheels and axles.
The student demonstrates the ability to apply conceptual knowledge of simple machines but
does not fully explain all aspects. The student appropriately suggests that it will take four people
to pull the elephant.
Expert
A detailed and labeled drawing of the idea is included. The picture clearly shows how the
elephant will be lifted and moved, using an inclined plane and wheel and axle. A complete
explanation is included that describes how the elephant will get onto the wagon and then how
the elephant will be moved across the gym. The forces for both lifting and moving the elephant
are identified. The student’s ability to apply knowledge of simple machines that combine two
machines to make a system is evident.
Simple Machines: Can You Design a Way to Lift and Move a 200-Pound Elephant?
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Novice
Simple Machines: Can You Design a Way to Lift and Move a 200-Pound Elephant?
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Apprentice
Simple Machines: Can You Design a Way to Lift and Move a 200-Pound Elephant?
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Practitioner
Simple Machines: Can You Design a Way to Lift and Move a 200-Pound Elephant?
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Expert
Simple Machines: Can You Design a Way to Lift and Move a 200-Pound Elephant?
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